mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
# include <linux/debugfs.h>
# include <linux/mm.h>
# include <linux/slab.h>
# include <linux/uaccess.h>
# include <linux/bootmem.h>
# include <linux/stacktrace.h>
# include <linux/page_owner.h>
2016-03-16 00:56:12 +03:00
# include <linux/jump_label.h>
2016-03-16 00:56:18 +03:00
# include <linux/migrate.h>
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
# include <linux/stackdepot.h>
2016-10-08 02:58:21 +03:00
# include <linux/seq_file.h>
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
# include "internal.h"
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
/*
* TODO : teach PAGE_OWNER_STACK_DEPTH ( __dump_page_owner and save_stack )
* to use off stack temporal storage
*/
# define PAGE_OWNER_STACK_DEPTH (16)
2016-10-08 02:58:30 +03:00
struct page_owner {
unsigned int order ;
gfp_t gfp_mask ;
int last_migrate_reason ;
depot_stack_handle_t handle ;
} ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
static bool page_owner_disabled = true ;
2016-03-16 00:56:12 +03:00
DEFINE_STATIC_KEY_FALSE ( page_owner_inited ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
static depot_stack_handle_t dummy_handle ;
static depot_stack_handle_t failure_handle ;
2017-09-07 02:20:44 +03:00
static depot_stack_handle_t early_handle ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
static void init_early_allocated_pages ( void ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
static int early_page_owner_param ( char * buf )
{
if ( ! buf )
return - EINVAL ;
if ( strcmp ( buf , " on " ) = = 0 )
page_owner_disabled = false ;
return 0 ;
}
early_param ( " page_owner " , early_page_owner_param ) ;
static bool need_page_owner ( void )
{
if ( page_owner_disabled )
return false ;
return true ;
}
2017-09-07 02:20:44 +03:00
static __always_inline depot_stack_handle_t create_dummy_stack ( void )
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
{
unsigned long entries [ 4 ] ;
struct stack_trace dummy ;
dummy . nr_entries = 0 ;
dummy . max_entries = ARRAY_SIZE ( entries ) ;
dummy . entries = & entries [ 0 ] ;
dummy . skip = 0 ;
save_stack_trace ( & dummy ) ;
2017-09-07 02:20:44 +03:00
return depot_save_stack ( & dummy , GFP_KERNEL ) ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
}
2017-09-07 02:20:44 +03:00
static noinline void register_dummy_stack ( void )
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
{
2017-09-07 02:20:44 +03:00
dummy_handle = create_dummy_stack ( ) ;
}
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
2017-09-07 02:20:44 +03:00
static noinline void register_failure_stack ( void )
{
failure_handle = create_dummy_stack ( ) ;
}
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
2017-09-07 02:20:44 +03:00
static noinline void register_early_stack ( void )
{
early_handle = create_dummy_stack ( ) ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
}
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
static void init_page_owner ( void )
{
if ( page_owner_disabled )
return ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
register_dummy_stack ( ) ;
register_failure_stack ( ) ;
2017-09-07 02:20:44 +03:00
register_early_stack ( ) ;
2016-03-16 00:56:12 +03:00
static_branch_enable ( & page_owner_inited ) ;
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
init_early_allocated_pages ( ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
}
struct page_ext_operations page_owner_ops = {
2016-10-08 02:58:30 +03:00
. size = sizeof ( struct page_owner ) ,
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
. need = need_page_owner ,
. init = init_page_owner ,
} ;
2016-10-08 02:58:30 +03:00
static inline struct page_owner * get_page_owner ( struct page_ext * page_ext )
{
return ( void * ) page_ext + page_owner_ops . offset ;
}
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
void __reset_page_owner ( struct page * page , unsigned int order )
{
int i ;
struct page_ext * page_ext ;
for ( i = 0 ; i < ( 1 < < order ) ; i + + ) {
page_ext = lookup_page_ext ( page + i ) ;
2016-06-04 00:55:38 +03:00
if ( unlikely ( ! page_ext ) )
continue ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
__clear_bit ( PAGE_EXT_OWNER , & page_ext - > flags ) ;
}
}
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
static inline bool check_recursive_alloc ( struct stack_trace * trace ,
unsigned long ip )
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
{
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
int i , count ;
if ( ! trace - > nr_entries )
return false ;
for ( i = 0 , count = 0 ; i < trace - > nr_entries ; i + + ) {
if ( trace - > entries [ i ] = = ip & & + + count = = 2 )
return true ;
}
2016-06-04 00:55:38 +03:00
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
return false ;
}
static noinline depot_stack_handle_t save_stack ( gfp_t flags )
{
unsigned long entries [ PAGE_OWNER_STACK_DEPTH ] ;
2015-02-12 02:28:34 +03:00
struct stack_trace trace = {
. nr_entries = 0 ,
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
. entries = entries ,
. max_entries = PAGE_OWNER_STACK_DEPTH ,
2017-09-14 02:28:35 +03:00
. skip = 2
2015-02-12 02:28:34 +03:00
} ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
depot_stack_handle_t handle ;
save_stack_trace ( & trace ) ;
if ( trace . nr_entries ! = 0 & &
trace . entries [ trace . nr_entries - 1 ] = = ULONG_MAX )
trace . nr_entries - - ;
/*
* We need to check recursion here because our request to stackdepot
* could trigger memory allocation to save new entry . New memory
* allocation would reach here and call depot_save_stack ( ) again
* if we don ' t catch it . There is still not enough memory in stackdepot
* so it would try to allocate memory again and loop forever .
*/
if ( check_recursive_alloc ( & trace , _RET_IP_ ) )
return dummy_handle ;
handle = depot_save_stack ( & trace , flags ) ;
if ( ! handle )
handle = failure_handle ;
return handle ;
}
2017-09-07 02:20:44 +03:00
static inline void __set_page_owner_handle ( struct page_ext * page_ext ,
depot_stack_handle_t handle , unsigned int order , gfp_t gfp_mask )
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
{
2016-10-08 02:58:30 +03:00
struct page_owner * page_owner ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
2016-10-08 02:58:30 +03:00
page_owner = get_page_owner ( page_ext ) ;
2017-09-07 02:20:44 +03:00
page_owner - > handle = handle ;
2016-10-08 02:58:30 +03:00
page_owner - > order = order ;
page_owner - > gfp_mask = gfp_mask ;
page_owner - > last_migrate_reason = - 1 ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
__set_bit ( PAGE_EXT_OWNER , & page_ext - > flags ) ;
}
2017-09-07 02:20:44 +03:00
noinline void __set_page_owner ( struct page * page , unsigned int order ,
gfp_t gfp_mask )
{
struct page_ext * page_ext = lookup_page_ext ( page ) ;
depot_stack_handle_t handle ;
if ( unlikely ( ! page_ext ) )
return ;
handle = save_stack ( gfp_mask ) ;
__set_page_owner_handle ( page_ext , handle , order , gfp_mask ) ;
}
2016-03-16 00:56:18 +03:00
void __set_page_owner_migrate_reason ( struct page * page , int reason )
{
struct page_ext * page_ext = lookup_page_ext ( page ) ;
2016-10-08 02:58:30 +03:00
struct page_owner * page_owner ;
2016-06-04 00:55:38 +03:00
if ( unlikely ( ! page_ext ) )
return ;
2016-03-16 00:56:18 +03:00
2016-10-08 02:58:30 +03:00
page_owner = get_page_owner ( page_ext ) ;
page_owner - > last_migrate_reason = reason ;
2016-03-16 00:56:18 +03:00
}
2016-07-27 01:23:49 +03:00
void __split_page_owner ( struct page * page , unsigned int order )
2015-07-18 02:24:18 +03:00
{
2016-07-27 01:23:49 +03:00
int i ;
2015-07-18 02:24:18 +03:00
struct page_ext * page_ext = lookup_page_ext ( page ) ;
2016-10-08 02:58:30 +03:00
struct page_owner * page_owner ;
2016-07-27 01:23:49 +03:00
2016-06-04 00:55:38 +03:00
if ( unlikely ( ! page_ext ) )
2016-07-27 01:23:49 +03:00
return ;
2015-07-18 02:24:18 +03:00
2016-10-08 02:58:30 +03:00
page_owner = get_page_owner ( page_ext ) ;
page_owner - > order = 0 ;
2016-07-27 01:23:49 +03:00
for ( i = 1 ; i < ( 1 < < order ) ; i + + )
__copy_page_owner ( page , page + i ) ;
2015-07-18 02:24:18 +03:00
}
2016-03-16 00:56:15 +03:00
void __copy_page_owner ( struct page * oldpage , struct page * newpage )
{
struct page_ext * old_ext = lookup_page_ext ( oldpage ) ;
struct page_ext * new_ext = lookup_page_ext ( newpage ) ;
2016-10-08 02:58:30 +03:00
struct page_owner * old_page_owner , * new_page_owner ;
2016-03-16 00:56:15 +03:00
2016-06-04 00:55:38 +03:00
if ( unlikely ( ! old_ext | | ! new_ext ) )
return ;
2016-10-08 02:58:30 +03:00
old_page_owner = get_page_owner ( old_ext ) ;
new_page_owner = get_page_owner ( new_ext ) ;
new_page_owner - > order = old_page_owner - > order ;
new_page_owner - > gfp_mask = old_page_owner - > gfp_mask ;
new_page_owner - > last_migrate_reason =
old_page_owner - > last_migrate_reason ;
new_page_owner - > handle = old_page_owner - > handle ;
2016-03-16 00:56:15 +03:00
/*
* We don ' t clear the bit on the oldpage as it ' s going to be freed
* after migration . Until then , the info can be useful in case of
* a bug , and the overal stats will be off a bit only temporarily .
* Also , migrate_misplaced_transhuge_page ( ) can still fail the
* migration and then we want the oldpage to retain the info . But
* in that case we also don ' t need to explicitly clear the info from
* the new page , which will be freed .
*/
__set_bit ( PAGE_EXT_OWNER , & new_ext - > flags ) ;
}
2016-10-08 02:58:21 +03:00
void pagetypeinfo_showmixedcount_print ( struct seq_file * m ,
pg_data_t * pgdat , struct zone * zone )
{
struct page * page ;
struct page_ext * page_ext ;
2016-10-08 02:58:30 +03:00
struct page_owner * page_owner ;
2016-10-08 02:58:21 +03:00
unsigned long pfn = zone - > zone_start_pfn , block_end_pfn ;
unsigned long end_pfn = pfn + zone - > spanned_pages ;
unsigned long count [ MIGRATE_TYPES ] = { 0 , } ;
int pageblock_mt , page_mt ;
int i ;
/* Scan block by block. First and last block may be incomplete */
pfn = zone - > zone_start_pfn ;
/*
* Walk the zone in pageblock_nr_pages steps . If a page block spans
* a zone boundary , it will be double counted between zones . This does
* not matter as the mixed block count will still be correct
*/
for ( ; pfn < end_pfn ; ) {
if ( ! pfn_valid ( pfn ) ) {
pfn = ALIGN ( pfn + 1 , MAX_ORDER_NR_PAGES ) ;
continue ;
}
block_end_pfn = ALIGN ( pfn + 1 , pageblock_nr_pages ) ;
block_end_pfn = min ( block_end_pfn , end_pfn ) ;
page = pfn_to_page ( pfn ) ;
pageblock_mt = get_pageblock_migratetype ( page ) ;
for ( ; pfn < block_end_pfn ; pfn + + ) {
if ( ! pfn_valid_within ( pfn ) )
continue ;
page = pfn_to_page ( pfn ) ;
if ( page_zone ( page ) ! = zone )
continue ;
if ( PageBuddy ( page ) ) {
2017-07-11 01:49:17 +03:00
unsigned long freepage_order ;
freepage_order = page_order_unsafe ( page ) ;
if ( freepage_order < MAX_ORDER )
pfn + = ( 1UL < < freepage_order ) - 1 ;
2016-10-08 02:58:21 +03:00
continue ;
}
if ( PageReserved ( page ) )
continue ;
page_ext = lookup_page_ext ( page ) ;
if ( unlikely ( ! page_ext ) )
continue ;
if ( ! test_bit ( PAGE_EXT_OWNER , & page_ext - > flags ) )
continue ;
2016-10-08 02:58:30 +03:00
page_owner = get_page_owner ( page_ext ) ;
page_mt = gfpflags_to_migratetype (
page_owner - > gfp_mask ) ;
2016-10-08 02:58:21 +03:00
if ( pageblock_mt ! = page_mt ) {
if ( is_migrate_cma ( pageblock_mt ) )
count [ MIGRATE_MOVABLE ] + + ;
else
count [ pageblock_mt ] + + ;
pfn = block_end_pfn ;
break ;
}
2016-10-08 02:58:30 +03:00
pfn + = ( 1UL < < page_owner - > order ) - 1 ;
2016-10-08 02:58:21 +03:00
}
}
/* Print counts */
seq_printf ( m , " Node %d, zone %8s " , pgdat - > node_id , zone - > name ) ;
for ( i = 0 ; i < MIGRATE_TYPES ; i + + )
seq_printf ( m , " %12lu " , count [ i ] ) ;
seq_putc ( m , ' \n ' ) ;
}
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
static ssize_t
print_page_owner ( char __user * buf , size_t count , unsigned long pfn ,
2016-10-08 02:58:30 +03:00
struct page * page , struct page_owner * page_owner ,
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
depot_stack_handle_t handle )
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
{
int ret ;
int pageblock_mt , page_mt ;
char * kbuf ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
unsigned long entries [ PAGE_OWNER_STACK_DEPTH ] ;
2015-02-12 02:28:34 +03:00
struct stack_trace trace = {
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
. nr_entries = 0 ,
. entries = entries ,
. max_entries = PAGE_OWNER_STACK_DEPTH ,
. skip = 0
2015-02-12 02:28:34 +03:00
} ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
kbuf = kmalloc ( count , GFP_KERNEL ) ;
if ( ! kbuf )
return - ENOMEM ;
ret = snprintf ( kbuf , count ,
mm, page_owner: print migratetype of page and pageblock, symbolic flags
The information in /sys/kernel/debug/page_owner includes the migratetype
of the pageblock the page belongs to. This is also checked against the
page's migratetype (as declared by gfp_flags during its allocation), and
the page is reported as Fallback if its migratetype differs from the
pageblock's one. t This is somewhat misleading because in fact fallback
allocation is not the only reason why these two can differ. It also
doesn't direcly provide the page's migratetype, although it's possible
to derive that from the gfp_flags.
It's arguably better to print both page and pageblock's migratetype and
leave the interpretation to the consumer than to suggest fallback
allocation as the only possible reason. While at it, we can print the
migratetypes as string the same way as /proc/pagetypeinfo does, as some
of the numeric values depend on kernel configuration. For that, this
patch moves the migratetype_names array from #ifdef CONFIG_PROC_FS part
of mm/vmstat.c to mm/page_alloc.c and exports it.
With the new format strings for flags, we can now also provide symbolic
page and gfp flags in the /sys/kernel/debug/page_owner file. This
replaces the positional printing of page flags as single letters, which
might have looked nicer, but was limited to a subset of flags, and
required the user to remember the letters.
Example page_owner entry after the patch:
Page allocated via order 0, mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY)
PFN 520 type Movable Block 1 type Movable Flags 0xfffff8001006c(referenced|uptodate|lru|active|mappedtodisk)
[<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230
[<ffffffff811b4058>] alloc_pages_current+0x88/0x120
[<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120
[<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240
[<ffffffff8116bd05>] ondemand_readahead+0x135/0x260
[<ffffffff8116bfb1>] page_cache_sync_readahead+0x31/0x50
[<ffffffff81160523>] generic_file_read_iter+0x453/0x760
[<ffffffff811e0d57>] __vfs_read+0xa7/0xd0
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-16 00:56:08 +03:00
" Page allocated via order %u, mask %#x(%pGg) \n " ,
2016-10-08 02:58:30 +03:00
page_owner - > order , page_owner - > gfp_mask ,
& page_owner - > gfp_mask ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
if ( ret > = count )
goto err ;
/* Print information relevant to grouping pages by mobility */
2016-05-20 03:14:27 +03:00
pageblock_mt = get_pageblock_migratetype ( page ) ;
2016-10-08 02:58:30 +03:00
page_mt = gfpflags_to_migratetype ( page_owner - > gfp_mask ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
ret + = snprintf ( kbuf + ret , count - ret ,
mm, page_owner: print migratetype of page and pageblock, symbolic flags
The information in /sys/kernel/debug/page_owner includes the migratetype
of the pageblock the page belongs to. This is also checked against the
page's migratetype (as declared by gfp_flags during its allocation), and
the page is reported as Fallback if its migratetype differs from the
pageblock's one. t This is somewhat misleading because in fact fallback
allocation is not the only reason why these two can differ. It also
doesn't direcly provide the page's migratetype, although it's possible
to derive that from the gfp_flags.
It's arguably better to print both page and pageblock's migratetype and
leave the interpretation to the consumer than to suggest fallback
allocation as the only possible reason. While at it, we can print the
migratetypes as string the same way as /proc/pagetypeinfo does, as some
of the numeric values depend on kernel configuration. For that, this
patch moves the migratetype_names array from #ifdef CONFIG_PROC_FS part
of mm/vmstat.c to mm/page_alloc.c and exports it.
With the new format strings for flags, we can now also provide symbolic
page and gfp flags in the /sys/kernel/debug/page_owner file. This
replaces the positional printing of page flags as single letters, which
might have looked nicer, but was limited to a subset of flags, and
required the user to remember the letters.
Example page_owner entry after the patch:
Page allocated via order 0, mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY)
PFN 520 type Movable Block 1 type Movable Flags 0xfffff8001006c(referenced|uptodate|lru|active|mappedtodisk)
[<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230
[<ffffffff811b4058>] alloc_pages_current+0x88/0x120
[<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120
[<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240
[<ffffffff8116bd05>] ondemand_readahead+0x135/0x260
[<ffffffff8116bfb1>] page_cache_sync_readahead+0x31/0x50
[<ffffffff81160523>] generic_file_read_iter+0x453/0x760
[<ffffffff811e0d57>] __vfs_read+0xa7/0xd0
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-16 00:56:08 +03:00
" PFN %lu type %s Block %lu type %s Flags %#lx(%pGp) \n " ,
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
pfn ,
mm, page_owner: print migratetype of page and pageblock, symbolic flags
The information in /sys/kernel/debug/page_owner includes the migratetype
of the pageblock the page belongs to. This is also checked against the
page's migratetype (as declared by gfp_flags during its allocation), and
the page is reported as Fallback if its migratetype differs from the
pageblock's one. t This is somewhat misleading because in fact fallback
allocation is not the only reason why these two can differ. It also
doesn't direcly provide the page's migratetype, although it's possible
to derive that from the gfp_flags.
It's arguably better to print both page and pageblock's migratetype and
leave the interpretation to the consumer than to suggest fallback
allocation as the only possible reason. While at it, we can print the
migratetypes as string the same way as /proc/pagetypeinfo does, as some
of the numeric values depend on kernel configuration. For that, this
patch moves the migratetype_names array from #ifdef CONFIG_PROC_FS part
of mm/vmstat.c to mm/page_alloc.c and exports it.
With the new format strings for flags, we can now also provide symbolic
page and gfp flags in the /sys/kernel/debug/page_owner file. This
replaces the positional printing of page flags as single letters, which
might have looked nicer, but was limited to a subset of flags, and
required the user to remember the letters.
Example page_owner entry after the patch:
Page allocated via order 0, mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY)
PFN 520 type Movable Block 1 type Movable Flags 0xfffff8001006c(referenced|uptodate|lru|active|mappedtodisk)
[<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230
[<ffffffff811b4058>] alloc_pages_current+0x88/0x120
[<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120
[<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240
[<ffffffff8116bd05>] ondemand_readahead+0x135/0x260
[<ffffffff8116bfb1>] page_cache_sync_readahead+0x31/0x50
[<ffffffff81160523>] generic_file_read_iter+0x453/0x760
[<ffffffff811e0d57>] __vfs_read+0xa7/0xd0
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-16 00:56:08 +03:00
migratetype_names [ page_mt ] ,
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
pfn > > pageblock_order ,
mm, page_owner: print migratetype of page and pageblock, symbolic flags
The information in /sys/kernel/debug/page_owner includes the migratetype
of the pageblock the page belongs to. This is also checked against the
page's migratetype (as declared by gfp_flags during its allocation), and
the page is reported as Fallback if its migratetype differs from the
pageblock's one. t This is somewhat misleading because in fact fallback
allocation is not the only reason why these two can differ. It also
doesn't direcly provide the page's migratetype, although it's possible
to derive that from the gfp_flags.
It's arguably better to print both page and pageblock's migratetype and
leave the interpretation to the consumer than to suggest fallback
allocation as the only possible reason. While at it, we can print the
migratetypes as string the same way as /proc/pagetypeinfo does, as some
of the numeric values depend on kernel configuration. For that, this
patch moves the migratetype_names array from #ifdef CONFIG_PROC_FS part
of mm/vmstat.c to mm/page_alloc.c and exports it.
With the new format strings for flags, we can now also provide symbolic
page and gfp flags in the /sys/kernel/debug/page_owner file. This
replaces the positional printing of page flags as single letters, which
might have looked nicer, but was limited to a subset of flags, and
required the user to remember the letters.
Example page_owner entry after the patch:
Page allocated via order 0, mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY)
PFN 520 type Movable Block 1 type Movable Flags 0xfffff8001006c(referenced|uptodate|lru|active|mappedtodisk)
[<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230
[<ffffffff811b4058>] alloc_pages_current+0x88/0x120
[<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120
[<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240
[<ffffffff8116bd05>] ondemand_readahead+0x135/0x260
[<ffffffff8116bfb1>] page_cache_sync_readahead+0x31/0x50
[<ffffffff81160523>] generic_file_read_iter+0x453/0x760
[<ffffffff811e0d57>] __vfs_read+0xa7/0xd0
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-16 00:56:08 +03:00
migratetype_names [ pageblock_mt ] ,
page - > flags , & page - > flags ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
if ( ret > = count )
goto err ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
depot_fetch_stack ( handle , & trace ) ;
2015-02-12 02:28:34 +03:00
ret + = snprint_stack_trace ( kbuf + ret , count - ret , & trace , 0 ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
if ( ret > = count )
goto err ;
2016-10-08 02:58:30 +03:00
if ( page_owner - > last_migrate_reason ! = - 1 ) {
2016-03-16 00:56:18 +03:00
ret + = snprintf ( kbuf + ret , count - ret ,
" Page has been migrated, last migrate reason: %s \n " ,
2016-10-08 02:58:30 +03:00
migrate_reason_names [ page_owner - > last_migrate_reason ] ) ;
2016-03-16 00:56:18 +03:00
if ( ret > = count )
goto err ;
}
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
ret + = snprintf ( kbuf + ret , count - ret , " \n " ) ;
if ( ret > = count )
goto err ;
if ( copy_to_user ( buf , kbuf , ret ) )
ret = - EFAULT ;
kfree ( kbuf ) ;
return ret ;
err :
kfree ( kbuf ) ;
return - ENOMEM ;
}
2016-03-16 00:56:21 +03:00
void __dump_page_owner ( struct page * page )
{
struct page_ext * page_ext = lookup_page_ext ( page ) ;
2016-10-08 02:58:30 +03:00
struct page_owner * page_owner ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
unsigned long entries [ PAGE_OWNER_STACK_DEPTH ] ;
2016-03-16 00:56:21 +03:00
struct stack_trace trace = {
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
. nr_entries = 0 ,
. entries = entries ,
. max_entries = PAGE_OWNER_STACK_DEPTH ,
. skip = 0
2016-03-16 00:56:21 +03:00
} ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
depot_stack_handle_t handle ;
2016-06-25 00:50:24 +03:00
gfp_t gfp_mask ;
int mt ;
2016-03-16 00:56:21 +03:00
2016-06-04 00:55:38 +03:00
if ( unlikely ( ! page_ext ) ) {
pr_alert ( " There is not page extension available. \n " ) ;
return ;
}
2016-10-08 02:58:30 +03:00
page_owner = get_page_owner ( page_ext ) ;
gfp_mask = page_owner - > gfp_mask ;
2016-06-25 00:50:24 +03:00
mt = gfpflags_to_migratetype ( gfp_mask ) ;
2016-06-04 00:55:38 +03:00
2016-03-16 00:56:21 +03:00
if ( ! test_bit ( PAGE_EXT_OWNER , & page_ext - > flags ) ) {
pr_alert ( " page_owner info is not active (free page?) \n " ) ;
return ;
}
2016-10-08 02:58:30 +03:00
handle = READ_ONCE ( page_owner - > handle ) ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
if ( ! handle ) {
pr_alert ( " page_owner info is not active (free page?) \n " ) ;
return ;
}
depot_fetch_stack ( handle , & trace ) ;
2016-03-18 00:19:47 +03:00
pr_alert ( " page allocated via order %u, migratetype %s, gfp_mask %#x(%pGg) \n " ,
2016-10-08 02:58:30 +03:00
page_owner - > order , migratetype_names [ mt ] , gfp_mask , & gfp_mask ) ;
2016-03-16 00:56:21 +03:00
print_stack_trace ( & trace , 0 ) ;
2016-10-08 02:58:30 +03:00
if ( page_owner - > last_migrate_reason ! = - 1 )
2016-03-16 00:56:21 +03:00
pr_alert ( " page has been migrated, last migrate reason: %s \n " ,
2016-10-08 02:58:30 +03:00
migrate_reason_names [ page_owner - > last_migrate_reason ] ) ;
2016-03-16 00:56:21 +03:00
}
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
static ssize_t
read_page_owner ( struct file * file , char __user * buf , size_t count , loff_t * ppos )
{
unsigned long pfn ;
struct page * page ;
struct page_ext * page_ext ;
2016-10-08 02:58:30 +03:00
struct page_owner * page_owner ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
depot_stack_handle_t handle ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
2016-03-16 00:56:12 +03:00
if ( ! static_branch_unlikely ( & page_owner_inited ) )
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
return - EINVAL ;
page = NULL ;
pfn = min_low_pfn + * ppos ;
/* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */
while ( ! pfn_valid ( pfn ) & & ( pfn & ( MAX_ORDER_NR_PAGES - 1 ) ) ! = 0 )
pfn + + ;
drain_all_pages ( NULL ) ;
/* Find an allocated page */
for ( ; pfn < max_pfn ; pfn + + ) {
/*
* If the new page is in a new MAX_ORDER_NR_PAGES area ,
* validate the area as existing , skip it if not
*/
if ( ( pfn & ( MAX_ORDER_NR_PAGES - 1 ) ) = = 0 & & ! pfn_valid ( pfn ) ) {
pfn + = MAX_ORDER_NR_PAGES - 1 ;
continue ;
}
/* Check for holes within a MAX_ORDER area */
if ( ! pfn_valid_within ( pfn ) )
continue ;
page = pfn_to_page ( pfn ) ;
if ( PageBuddy ( page ) ) {
unsigned long freepage_order = page_order_unsafe ( page ) ;
if ( freepage_order < MAX_ORDER )
pfn + = ( 1UL < < freepage_order ) - 1 ;
continue ;
}
page_ext = lookup_page_ext ( page ) ;
2016-06-04 00:55:38 +03:00
if ( unlikely ( ! page_ext ) )
continue ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
/*
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
* Some pages could be missed by concurrent allocation or free ,
* because we don ' t hold the zone lock .
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
*/
if ( ! test_bit ( PAGE_EXT_OWNER , & page_ext - > flags ) )
continue ;
2016-10-08 02:58:30 +03:00
page_owner = get_page_owner ( page_ext ) ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
/*
* Access to page_ext - > handle isn ' t synchronous so we should
* be careful to access it .
*/
2016-10-08 02:58:30 +03:00
handle = READ_ONCE ( page_owner - > handle ) ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
if ( ! handle )
continue ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
/* Record the next PFN to read in the file offset */
* ppos = ( pfn - min_low_pfn ) + 1 ;
mm/page_owner: use stackdepot to store stacktrace
Currently, we store each page's allocation stacktrace on corresponding
page_ext structure and it requires a lot of memory. This causes the
problem that memory tight system doesn't work well if page_owner is
enabled. Moreover, even with this large memory consumption, we cannot
get full stacktrace because we allocate memory at boot time and just
maintain 8 stacktrace slots to balance memory consumption. We could
increase it to more but it would make system unusable or change system
behaviour.
To solve the problem, this patch uses stackdepot to store stacktrace.
It obviously provides memory saving but there is a drawback that
stackdepot could fail.
stackdepot allocates memory at runtime so it could fail if system has
not enough memory. But, most of allocation stack are generated at very
early time and there are much memory at this time. So, failure would
not happen easily. And, one failure means that we miss just one page's
allocation stacktrace so it would not be a big problem. In this patch,
when memory allocation failure happens, we store special stracktrace
handle to the page that is failed to save stacktrace. With it, user can
guess memory usage properly even if failure happens.
Memory saving looks as following. (4GB memory system with page_owner)
(before the patch -> after the patch)
static allocation:
92274688 bytes -> 25165824 bytes
dynamic allocation after boot + kernel build:
0 bytes -> 327680 bytes
total:
92274688 bytes -> 25493504 bytes
72% reduction in total.
Note that implementation looks complex than someone would imagine
because there is recursion issue. stackdepot uses page allocator and
page_owner is called at page allocation. Using stackdepot in page_owner
could re-call page allcator and then page_owner. That is a recursion.
To detect and avoid it, whenever we obtain stacktrace, recursion is
checked and page_owner is set to dummy information if found. Dummy
information means that this page is allocated for page_owner feature
itself (such as stackdepot) and it's understandable behavior for user.
[iamjoonsoo.kim@lge.com: mm-page_owner-use-stackdepot-to-store-stacktrace-v3]
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1466150259-27727-7-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1464230275-25791-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27 01:23:55 +03:00
return print_page_owner ( buf , count , pfn , page ,
2016-10-08 02:58:30 +03:00
page_owner , handle ) ;
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
}
return 0 ;
}
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
static void init_pages_in_zone ( pg_data_t * pgdat , struct zone * zone )
{
struct page * page ;
struct page_ext * page_ext ;
unsigned long pfn = zone - > zone_start_pfn , block_end_pfn ;
unsigned long end_pfn = pfn + zone - > spanned_pages ;
unsigned long count = 0 ;
/* Scan block by block. First and last block may be incomplete */
pfn = zone - > zone_start_pfn ;
/*
* Walk the zone in pageblock_nr_pages steps . If a page block spans
* a zone boundary , it will be double counted between zones . This does
* not matter as the mixed block count will still be correct
*/
for ( ; pfn < end_pfn ; ) {
if ( ! pfn_valid ( pfn ) ) {
pfn = ALIGN ( pfn + 1 , MAX_ORDER_NR_PAGES ) ;
continue ;
}
block_end_pfn = ALIGN ( pfn + 1 , pageblock_nr_pages ) ;
block_end_pfn = min ( block_end_pfn , end_pfn ) ;
page = pfn_to_page ( pfn ) ;
for ( ; pfn < block_end_pfn ; pfn + + ) {
if ( ! pfn_valid_within ( pfn ) )
continue ;
page = pfn_to_page ( pfn ) ;
2016-05-20 03:12:13 +03:00
if ( page_zone ( page ) ! = zone )
continue ;
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
/*
2017-09-07 02:20:51 +03:00
* To avoid having to grab zone - > lock , be a little
* careful when reading buddy page order . The only
* danger is that we skip too much and potentially miss
* some early allocated pages , which is better than
* heavy lock contention .
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
*/
if ( PageBuddy ( page ) ) {
2017-09-07 02:20:51 +03:00
unsigned long order = page_order_unsafe ( page ) ;
if ( order > 0 & & order < MAX_ORDER )
pfn + = ( 1UL < < order ) - 1 ;
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
continue ;
}
if ( PageReserved ( page ) )
continue ;
page_ext = lookup_page_ext ( page ) ;
2016-06-04 00:55:38 +03:00
if ( unlikely ( ! page_ext ) )
continue ;
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
2017-09-07 02:20:44 +03:00
/* Maybe overlapping zone */
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
if ( test_bit ( PAGE_EXT_OWNER , & page_ext - > flags ) )
continue ;
/* Found early allocated page */
2017-09-07 02:20:44 +03:00
__set_page_owner_handle ( page_ext , early_handle , 0 , 0 ) ;
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
count + + ;
}
2017-09-07 02:20:51 +03:00
cond_resched ( ) ;
mm/page_owner: correct owner information for early allocated pages
Extended memory to store page owner information is initialized some time
later than that page allocator starts. Until initialization, many pages
can be allocated and they have no owner information. This make debugging
using page owner harder, so some fixup will be helpful.
This patch fixes up this situation by setting fake owner information
immediately after page extension is initialized. Information doesn't tell
the right owner, but, at least, it can tell whether page is allocated or
not, more correctly.
On my testing, this patch catches 13343 early allocated pages, although
they are mostly allocated from page extension feature. Anyway, after
then, there is no page left that it is allocated and has no page owner
flag.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:04 +03:00
}
pr_info ( " Node %d, zone %8s: page owner found early allocated %lu pages \n " ,
pgdat - > node_id , zone - > name , count ) ;
}
static void init_zones_in_node ( pg_data_t * pgdat )
{
struct zone * zone ;
struct zone * node_zones = pgdat - > node_zones ;
for ( zone = node_zones ; zone - node_zones < MAX_NR_ZONES ; + + zone ) {
if ( ! populated_zone ( zone ) )
continue ;
init_pages_in_zone ( pgdat , zone ) ;
}
}
static void init_early_allocated_pages ( void )
{
pg_data_t * pgdat ;
drain_all_pages ( NULL ) ;
for_each_online_pgdat ( pgdat )
init_zones_in_node ( pgdat ) ;
}
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
static const struct file_operations proc_page_owner_operations = {
. read = read_page_owner ,
} ;
static int __init pageowner_init ( void )
{
struct dentry * dentry ;
2016-03-16 00:56:12 +03:00
if ( ! static_branch_unlikely ( & page_owner_inited ) ) {
mm/page_owner: keep track of page owners
This is the page owner tracking code which is introduced so far ago. It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is. Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.
This functionality help us to know who allocates the page. When
allocating a page, we store some information about allocation in extra
memory. Later, if we need to know status of all pages, we can get and
analyze it from this stored information.
In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page. It enables us to turn on/off this feature at boottime
without considerable memory waste.
Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex. We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.
Moreover, we can use page_owner feature further for various purposes. For
example, we can use it for fragmentation statistics implemented in this
patch. And, I also plan to implement some CMA failure debugging feature
using this interface.
I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history. Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.
Contributor:
Alexander Nyberg <alexn@dsv.su.se>
Mel Gorman <mgorman@suse.de>
Dave Hansen <dave@linux.vnet.ibm.com>
Minchan Kim <minchan@kernel.org>
Michal Nazarewicz <mina86@mina86.com>
Andrew Morton <akpm@linux-foundation.org>
Jungsoo Son <jungsoo.son@lge.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 03:56:01 +03:00
pr_info ( " page_owner is disabled \n " ) ;
return 0 ;
}
dentry = debugfs_create_file ( " page_owner " , S_IRUSR , NULL ,
NULL , & proc_page_owner_operations ) ;
if ( IS_ERR ( dentry ) )
return PTR_ERR ( dentry ) ;
return 0 ;
}
2015-05-02 04:57:34 +03:00
late_initcall ( pageowner_init )