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mm: introduce __GFP_MEMALLOC to allow access to emergency reserves

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__GFP_MEMALLOC will allow the allocation to disregard the watermarks, much
like PF_MEMALLOC.  It allows one to pass along the memalloc state in
object related allocation flags as opposed to task related flags, such as
sk->sk_allocation.  This removes the need for ALLOC_PFMEMALLOC as callers
using __GFP_MEMALLOC can get the ALLOC_NO_WATERMARK flag which is now
enough to identify allocations related to page reclaim.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: David Miller <davem@davemloft.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mel Gorman 2012-07-31 16:44:03 -07:00 committed by Linus Torvalds
parent 5091b74a95
commit b37f1dd0f5
5 changed files with 21 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
include/linux/gfp.h
View File

@ -23,6 +23,7 @@ struct vm_area_struct;
#define ___GFP_REPEAT 0x400u #define ___GFP_REPEAT 0x400u
#define ___GFP_NOFAIL 0x800u #define ___GFP_NOFAIL 0x800u
#define ___GFP_NORETRY 0x1000u #define ___GFP_NORETRY 0x1000u
#define ___GFP_MEMALLOC 0x2000u
#define ___GFP_COMP 0x4000u #define ___GFP_COMP 0x4000u
#define ___GFP_ZERO 0x8000u #define ___GFP_ZERO 0x8000u
#define ___GFP_NOMEMALLOC 0x10000u #define ___GFP_NOMEMALLOC 0x10000u
@ -76,9 +77,14 @@ struct vm_area_struct;
#define __GFP_REPEAT ((__force gfp_t)___GFP_REPEAT) /* See above */ #define __GFP_REPEAT ((__force gfp_t)___GFP_REPEAT) /* See above */
#define __GFP_NOFAIL ((__force gfp_t)___GFP_NOFAIL) /* See above */ #define __GFP_NOFAIL ((__force gfp_t)___GFP_NOFAIL) /* See above */
#define __GFP_NORETRY ((__force gfp_t)___GFP_NORETRY) /* See above */ #define __GFP_NORETRY ((__force gfp_t)___GFP_NORETRY) /* See above */
#define __GFP_MEMALLOC ((__force gfp_t)___GFP_MEMALLOC)/* Allow access to emergency reserves */
#define __GFP_COMP ((__force gfp_t)___GFP_COMP) /* Add compound page metadata */ #define __GFP_COMP ((__force gfp_t)___GFP_COMP) /* Add compound page metadata */
#define __GFP_ZERO ((__force gfp_t)___GFP_ZERO) /* Return zeroed page on success */ #define __GFP_ZERO ((__force gfp_t)___GFP_ZERO) /* Return zeroed page on success */
#define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves */ #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC) /* Don't use emergency reserves.
* This takes precedence over the
* __GFP_MEMALLOC flag if both are
* set
*/
#define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL) /* Enforce hardwall cpuset memory allocs */ #define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL) /* Enforce hardwall cpuset memory allocs */
#define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE)/* No fallback, no policies */ #define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE)/* No fallback, no policies */
#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) /* Page is reclaimable */ #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) /* Page is reclaimable */
@ -129,7 +135,7 @@ struct vm_area_struct;
/* Control page allocator reclaim behavior */ /* Control page allocator reclaim behavior */
#define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\ #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
__GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\ __GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
__GFP_NORETRY|__GFP_NOMEMALLOC) __GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC)
/* Control slab gfp mask during early boot */ /* Control slab gfp mask during early boot */
#define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS)) #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS))

2
include/linux/mm_types.h
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@ -55,7 +55,7 @@ struct page {
pgoff_t index; /* Our offset within mapping. */ pgoff_t index; /* Our offset within mapping. */
void *freelist; /* slub/slob first free object */ void *freelist; /* slub/slob first free object */
bool pfmemalloc; /* If set by the page allocator, bool pfmemalloc; /* If set by the page allocator,
* ALLOC_PFMEMALLOC was set * ALLOC_NO_WATERMARKS was set
* and the low watermark was not * and the low watermark was not
* met implying that the system * met implying that the system
* is under some pressure. The * is under some pressure. The

1
include/trace/events/gfpflags.h
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@ -30,6 +30,7 @@
{(unsigned long)__GFP_COMP, "GFP_COMP"}, \ {(unsigned long)__GFP_COMP, "GFP_COMP"}, \
{(unsigned long)__GFP_ZERO, "GFP_ZERO"}, \ {(unsigned long)__GFP_ZERO, "GFP_ZERO"}, \
{(unsigned long)__GFP_NOMEMALLOC, "GFP_NOMEMALLOC"}, \ {(unsigned long)__GFP_NOMEMALLOC, "GFP_NOMEMALLOC"}, \
{(unsigned long)__GFP_MEMALLOC, "GFP_MEMALLOC"}, \
{(unsigned long)__GFP_HARDWALL, "GFP_HARDWALL"}, \ {(unsigned long)__GFP_HARDWALL, "GFP_HARDWALL"}, \
{(unsigned long)__GFP_THISNODE, "GFP_THISNODE"}, \ {(unsigned long)__GFP_THISNODE, "GFP_THISNODE"}, \
{(unsigned long)__GFP_RECLAIMABLE, "GFP_RECLAIMABLE"}, \ {(unsigned long)__GFP_RECLAIMABLE, "GFP_RECLAIMABLE"}, \

22
mm/page_alloc.c
View File

@ -1513,7 +1513,6 @@ failed:
#define ALLOC_HARDER 0x10 /* try to alloc harder */ #define ALLOC_HARDER 0x10 /* try to alloc harder */
#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
#define ALLOC_PFMEMALLOC 0x80 /* Caller has PF_MEMALLOC set */
#ifdef CONFIG_FAIL_PAGE_ALLOC #ifdef CONFIG_FAIL_PAGE_ALLOC
@ -2294,11 +2293,10 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
} else if (unlikely(rt_task(current)) && !in_interrupt()) } else if (unlikely(rt_task(current)) && !in_interrupt())
alloc_flags |= ALLOC_HARDER; alloc_flags |= ALLOC_HARDER;
if ((current->flags & PF_MEMALLOC) || if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
unlikely(test_thread_flag(TIF_MEMDIE))) { if (gfp_mask & __GFP_MEMALLOC)
alloc_flags |= ALLOC_PFMEMALLOC; alloc_flags |= ALLOC_NO_WATERMARKS;
else if (likely(!(gfp_mask & __GFP_NOMEMALLOC)) && !in_interrupt())
if (likely(!(gfp_mask & __GFP_NOMEMALLOC)) && !in_interrupt())
alloc_flags |= ALLOC_NO_WATERMARKS; alloc_flags |= ALLOC_NO_WATERMARKS;
} }
@ -2307,7 +2305,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
{ {
return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_PFMEMALLOC); return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
} }
static inline struct page * static inline struct page *
@ -2498,12 +2496,12 @@ nopage:
return page; return page;
got_pg: got_pg:
/* /*
* page->pfmemalloc is set when the caller had PFMEMALLOC set or is * page->pfmemalloc is set when the caller had PFMEMALLOC set, is
* been OOM killed. The expectation is that the caller is taking * been OOM killed or specified __GFP_MEMALLOC. The expectation is
* steps that will free more memory. The caller should avoid the * that the caller is taking steps that will free more memory. The
* page being used for !PFMEMALLOC purposes. * caller should avoid the page being used for !PFMEMALLOC purposes.
*/ */
page->pfmemalloc = !!(alloc_flags & ALLOC_PFMEMALLOC); page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);
if (kmemcheck_enabled) if (kmemcheck_enabled)
kmemcheck_pagealloc_alloc(page, order, gfp_mask); kmemcheck_pagealloc_alloc(page, order, gfp_mask);

2
mm/slab.c
View File

@ -1884,7 +1884,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
return NULL; return NULL;
} }
/* Record if ALLOC_PFMEMALLOC was set when allocating the slab */ /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
if (unlikely(page->pfmemalloc)) if (unlikely(page->pfmemalloc))
pfmemalloc_active = true; pfmemalloc_active = true;