Commit Graph

15927 Commits

Author SHA1 Message Date
Muchun Song
cae3af62b3 mm: memcontrol: fix swap undercounting in cgroup2
When pages are swapped in, the VM may retain the swap copy to avoid
repeated writes in the future.  It's also retained if shared pages are
faulted back in some processes, but not in others.  During that time we
have an in-memory copy of the page, as well as an on-swap copy.  Cgroup1
and cgroup2 handle these overlapping lifetimes slightly differently due to
the nature of how they account memory and swap:

Cgroup1 has a unified memory+swap counter that tracks a data page
regardless whether it's in-core or swapped out.  On swapin, we transfer
the charge from the swap entry to the newly allocated swapcache page, even
though the swap entry might stick around for a while.  That's why we have
a mem_cgroup_uncharge_swap() call inside mem_cgroup_charge().

Cgroup2 tracks memory and swap as separate, independent resources and thus
has split memory and swap counters.  On swapin, we charge the newly
allocated swapcache page as memory, while the swap slot in turn must
remain charged to the swap counter as long as its allocated too.

The cgroup2 logic was broken by commit 2d1c498072 ("mm: memcontrol: make
swap tracking an integral part of memory control"), because it
accidentally removed the do_memsw_account() check in the branch inside
mem_cgroup_uncharge() that was supposed to tell the difference between the
charge transfer in cgroup1 and the separate counters in cgroup2.

As a result, cgroup2 currently undercounts retained swap to varying
degrees: swap slots are cached up to 50% of the configured limit or total
available swap space; partially faulted back shared pages are only limited
by physical capacity.  This in turn allows cgroups to significantly
overconsume their alloted swap space.

Add the do_memsw_account() check back to fix this problem.

Link: https://lkml.kernel.org/r/20210217153237.92484-1-songmuchun@bytedance.com
Fixes: 2d1c498072 ("mm: memcontrol: make swap tracking an integral part of memory control")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>	[5.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:30 -08:00
Johannes Weiner
6eeb104e11 fs: buffer: use raw page_memcg() on locked page
alloc_page_buffers() currently uses get_mem_cgroup_from_page() for
charging the buffers to the page owner, which does an rcu-protected
page->memcg lookup and acquires a reference.  But buffer allocation has
the page lock held throughout, which pins the page to the memcg and
thereby the memcg - neither rcu nor holding an extra reference during the
allocation are necessary.  Use a raw page_memcg() instead.

This was the last user of get_mem_cgroup_from_page(), delete it.

Link: https://lkml.kernel.org/r/20210209190126.97842-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:30 -08:00
Shakeel Butt
a7b7e1df89 mm/list_lru.c: remove kvfree_rcu_local()
The list_lru file used to have local kvfree_rcu() which was renamed by
commit e0feed08ab ("mm/list_lru.c: Rename kvfree_rcu() to local
variant") to introduce the globally visible kvfree_rcu().

Now we have global kvfree_rcu(), so remove the local kvfree_rcu_local()
and just use the global one.

Link: https://lkml.kernel.org/r/20210207152148.1285842-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Uladzislau Rezki <urezki@gmail.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:30 -08:00
Muchun Song
c41a40b6ba mm: memcontrol: replace the loop with a list_for_each_entry()
The rule of list walk has gone since commit a9d5adeeb4
("mm/memcontrol: allow to uncharge page without using page->lru field")

So remove the strange comment and replace the loop with a
list_for_each_entry().

There is only one caller of the uncharge_list().  So just fold it into
mem_cgroup_uncharge_list() and remove it.

Link: https://lkml.kernel.org/r/20210204163055.56080-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:30 -08:00
Yang Li
8a260162f9 mm/memcontrol: remove redundant NULL check
Fix below warnings reported by coccicheck:

  mm/memcontrol.c:451:3-9: WARNING: NULL check before some freeing functions is not needed.

Link: https://lkml.kernel.org/r/1611216029-34397-1-git-send-email-abaci-bugfix@linux.alibaba.com
Signed-off-by: Yang Li <abaci-bugfix@linux.alibaba.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Roman Gushchin
c1a660dea3 mm: kmem: make __memcg_kmem_(un)charge static
I've noticed that __memcg_kmem_charge() and __memcg_kmem_uncharge() are
not used anywhere except memcontrol.c.  Yet they are not declared as
non-static and are declared in memcontrol.h.

This patch makes them static.

Link: https://lkml.kernel.org/r/20210108020332.4096911-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Shakeel Butt
b603894248 mm: memcg: add swapcache stat for memcg v2
This patch adds swapcache stat for the cgroup v2.  The swapcache
represents the memory that is accounted against both the memory and the
swap limit of the cgroup.  The main motivation behind exposing the
swapcache stat is for enabling users to gracefully migrate from cgroup
v1's memsw counter to cgroup v2's memory and swap counters.

Cgroup v1's memsw limit allows users to limit the memory+swap usage of a
workload but without control on the exact proportion of memory and swap.
Cgroup v2 provides separate limits for memory and swap which enables more
control on the exact usage of memory and swap individually for the
workload.

With some little subtleties, the v1's memsw limit can be switched with the
sum of the v2's memory and swap limits.  However the alternative for memsw
usage is not yet available in cgroup v2.  Exposing per-cgroup swapcache
stat enables that alternative.  Adding the memory usage and swap usage and
subtracting the swapcache will approximate the memsw usage.  This will
help in the transparent migration of the workloads depending on memsw
usage and limit to v2' memory and swap counters.

The reasons these applications are still interested in this approximate
memsw usage are: (1) these applications are not really interested in two
separate memory and swap usage metrics.  A single usage metric is more
simple to use and reason about for them.

(2) The memsw usage metric hides the underlying system's swap setup from
the applications.  Applications with multiple instances running in a
datacenter with heterogeneous systems (some have swap and some don't) will
keep seeing a consistent view of their usage.

[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]

Link: https://lkml.kernel.org/r/20210108155813.2914586-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Alex Shi
f9b1038ebc mm/memcg: remove rcu locking for lock_page_lruvec function series
lock_page_lruvec() and its variants used rcu_read_lock() with the
intention of safeguarding against the mem_cgroup being destroyed
concurrently; but so long as they are called under the specified
conditions (as they are), there is no way for the page's mem_cgroup to be
destroyed.  Delete the unnecessary rcu_read_lock() and _unlock().

Hugh Dickins polished the commit log.  Thanks a lot!

Link: https://lkml.kernel.org/r/1608614453-10739-2-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Alex Shi
d7e3aba583 mm/memcg: revise the using condition of lock_page_lruvec function series
lock_page_lruvec() and its variants are safe to use under the same
conditions as commit_charge(): add lock_page_memcg() to the comment.

Polished with Hugh Dickins' suggestions, thanks!

Link: https://lkml.kernel.org/r/1608614453-10739-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
fff66b79a1 mm: memcontrol: make the slab calculation consistent
Although the ratio of the slab is one, we also should read the ratio from
the related memory_stats instead of hard-coding.  And the local variable
of size is already the value of slab_unreclaimable.  So we do not need to
read again.

To do this we need some code like below:

if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) {
-	size = memcg_page_state(memcg, NR_SLAB_RECLAIMABLE_B) +
-	       memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE_B);
+       VM_BUG_ON(i < 1);
+       VM_BUG_ON(memory_stats[i - 1].idx != NR_SLAB_RECLAIMABLE_B);
+	size += memcg_page_state(memcg, memory_stats[i - 1].idx) *
+		memory_stats[i - 1].ratio;

It requires a series of VM_BUG_ONs or comments to ensure these two items
are actually adjacent and in the right order.  So it would probably be
easier to implement this using a wrapper that has a big switch() for unit
conversion.

More details about this discussion can refer to:

    https://lore.kernel.org/patchwork/patch/1348611/

This would fix the ratio inconsistency and get rid of the order
guarantee.

Link: https://lkml.kernel.org/r/20201228164110.2838-8-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
380780e718 mm: memcontrol: convert NR_FILE_PMDMAPPED account to pages
Currently we use struct per_cpu_nodestat to cache the vmstat counters,
which leads to inaccurate statistics especially THP vmstat counters.  In
the systems with hundreds of processors it can be GBs of memory.  For
example, for a 96 CPUs system, the threshold is the maximum number of 125.
And the per cpu counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth
of memory in one go) so skipping the batching seems like sensible.
Although every THP stats update overflows the per-cpu counter, resorting
to atomic global updates.  But it can make the statistics more accuracy
for the THP vmstat counters.

So we convert the NR_FILE_PMDMAPPED account to pages.  This patch is
consistent with 8f182270df ("mm/swap.c: flush lru pvecs on compound page
arrival").  Doing this also can make the unit of vmstat counters more
unified.  Finally, the unit of the vmstat counters are pages, kB and
bytes.  The B/KB suffix can tell us that the unit is bytes or kB.  The
rest which is without suffix are pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-7-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
a1528e21f8 mm: memcontrol: convert NR_SHMEM_PMDMAPPED account to pages
Currently we use struct per_cpu_nodestat to cache the vmstat counters,
which leads to inaccurate statistics especially THP vmstat counters.  In
the systems with hundreds of processors it can be GBs of memory.  For
example, for a 96 CPUs system, the threshold is the maximum number of 125.
And the per cpu counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth
of memory in one go) so skipping the batching seems like sensible.
Although every THP stats update overflows the per-cpu counter, resorting
to atomic global updates.  But it can make the statistics more accuracy
for the THP vmstat counters.

So we convert the NR_SHMEM_PMDMAPPED account to pages.  This patch is
consistent with 8f182270df ("mm/swap.c: flush lru pvecs on compound page
arrival").  Doing this also can make the unit of vmstat counters more
unified.  Finally, the unit of the vmstat counters are pages, kB and
bytes.  The B/KB suffix can tell us that the unit is bytes or kB.  The
rest which is without suffix are pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-6-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
57b2847d3c mm: memcontrol: convert NR_SHMEM_THPS account to pages
Currently we use struct per_cpu_nodestat to cache the vmstat counters,
which leads to inaccurate statistics especially THP vmstat counters.  In
the systems with hundreds of processors it can be GBs of memory.  For
example, for a 96 CPUs system, the threshold is the maximum number of 125.
And the per cpu counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth
of memory in one go) so skipping the batching seems like sensible.
Although every THP stats update overflows the per-cpu counter, resorting
to atomic global updates.  But it can make the statistics more accuracy
for the THP vmstat counters.

So we convert the NR_SHMEM_THPS account to pages.  This patch is
consistent with 8f182270df ("mm/swap.c: flush lru pvecs on compound page
arrival").  Doing this also can make the unit of vmstat counters more
unified.  Finally, the unit of the vmstat counters are pages, kB and
bytes.  The B/KB suffix can tell us that the unit is bytes or kB.  The
rest which is without suffix are pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
bf9ecead53 mm: memcontrol: convert NR_FILE_THPS account to pages
Currently we use struct per_cpu_nodestat to cache the vmstat counters,
which leads to inaccurate statistics especially THP vmstat counters.  In
the systems with if hundreds of processors it can be GBs of memory.  For
example, for a 96 CPUs system, the threshold is the maximum number of 125.
And the per cpu counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth
of memory in one go) so skipping the batching seems like sensible.
Although every THP stats update overflows the per-cpu counter, resorting
to atomic global updates.  But it can make the statistics more accuracy
for the THP vmstat counters.

So we convert the NR_FILE_THPS account to pages.  This patch is consistent
with 8f182270df ("mm/swap.c: flush lru pvecs on compound page arrival").
Doing this also can make the unit of vmstat counters more unified.
Finally, the unit of the vmstat counters are pages, kB and bytes.  The
B/KB suffix can tell us that the unit is bytes or kB.  The rest which is
without suffix are pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
69473e5de8 mm: memcontrol: convert NR_ANON_THPS account to pages
Currently we use struct per_cpu_nodestat to cache the vmstat counters,
which leads to inaccurate statistics especially THP vmstat counters.  In
the systems with hundreds of processors it can be GBs of memory.  For
example, for a 96 CPUs system, the threshold is the maximum number of 125.
And the per cpu counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth
of memory in one go) so skipping the batching seems like sensible.
Although every THP stats update overflows the per-cpu counter, resorting
to atomic global updates.  But it can make the statistics more accuracy
for the THP vmstat counters.

So we convert the NR_ANON_THPS account to pages.  This patch is consistent
with 8f182270df ("mm/swap.c: flush lru pvecs on compound page arrival").
Doing this also can make the unit of vmstat counters more unified.
Finally, the unit of the vmstat counters are pages, kB and bytes.  The
B/KB suffix can tell us that the unit is bytes or kB.  The rest which is
without suffix are pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-3-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
b0ba3bff3e mm: memcontrol: fix NR_ANON_THPS accounting in charge moving
Patch series "Convert all THP vmstat counters to pages", v6.

This patch series is aimed to convert all THP vmstat counters to pages.

The unit of some vmstat counters are pages, some are bytes, some are
HPAGE_PMD_NR, and some are KiB. When we want to expose these vmstat
counters to the userspace, we have to know the unit of the vmstat counters
is which one. When the unit is bytes or kB, both clearly distinguishable
by the B/KB suffix. But for the THP vmstat counters, we may make mistakes.

For example, the below is some bug fix for the THP vmstat counters:

  - 7de2e9f195 ("mm: memcontrol: correct the NR_ANON_THPS counter of hierarchical memcg")
  - The first commit in this series ("fix NR_ANON_THPS accounting in charge moving")

This patch series can make the code clear. And make all the unit of the THP
vmstat counters in pages. Finally, the unit of the vmstat counters are
pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes
or kB. The rest which is without suffix are pages.

In this series, I changed the following vmstat counters unit from HPAGE_PMD_NR
to pages. However, there is no change to the print format of output to user
space.

  - NR_ANON_THPS
  - NR_FILE_THPS
  - NR_SHMEM_THPS
  - NR_SHMEM_PMDMAPPED
  - NR_FILE_PMDMAPPED

Doing this also can make the statistics more accuracy for the THP vmstat
counters. This series is consistent with 8f182270df ("mm/swap.c: flush lru
pvecs on compound page arrival").

Because we use struct per_cpu_nodestat to cache the vmstat counters, which
leads to inaccurate statistics especially THP vmstat counters. In the systems
with hundreds of processors it can be GBs of memory. For example, for a 96
CPUs system, the threshold is the maximum number of 125. And the per cpu
counters can cache 23.4375 GB in total.

The THP page is already a form of batched addition (it will add 512 worth of
memory in one go) so skipping the batching seems like sensible. Although every
THP stats update overflows the per-cpu counter, resorting to atomic global
updates. But it can make the statistics more accuracy for the THP vmstat
counters. From this point of view, I think that do this converting is
reasonable.

Thanks Hugh for mentioning this. This was inspired by Johannes and Roman.
Thanks to them.

This patch (of 7):

The unit of NR_ANON_THPS is HPAGE_PMD_NR already.  So it should inc/dec by
one rather than nr_pages.

Link: https://lkml.kernel.org/r/20201228164110.2838-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20201228164110.2838-2-songmuchun@bytedance.com
Fixes: 468c398233 ("mm: memcontrol: switch to native NR_ANON_THPS counter")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Rafael. J. Wysocki <rafael@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Muchun Song
f3344adf38 mm: memcontrol: optimize per-lruvec stats counter memory usage
The vmstat threshold is 32 (MEMCG_CHARGE_BATCH), Actually the threshold
can be as big as MEMCG_CHARGE_BATCH * PAGE_SIZE.  It still fits into s32.
So introduce struct batched_lruvec_stat to optimize memory usage.

The size of struct lruvec_stat is 304 bytes on 64 bit systems.  As it is a
per-cpu structure.  So with this patch, we can save 304 / 2 * ncpu bytes
per-memcg per-node where ncpu is the number of the possible CPU.  If there
are c memory cgroup (include dying cgroup) and n NUMA node in the system.
Finally, we can save (152 * ncpu * c * n) bytes.

[akpm@linux-foundation.org: fix typo in comment]

Link: https://lkml.kernel.org/r/20201210042121.39665-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Chris Down <chris@chrisdown.name>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Roman Gushchin
2e9bd48315 mm: memcg/slab: pre-allocate obj_cgroups for slab caches with SLAB_ACCOUNT
In general it's unknown in advance if a slab page will contain accounted
objects or not.  In order to avoid memory waste, an obj_cgroup vector is
allocated dynamically when a need to account of a new object arises.  Such
approach is memory efficient, but requires an expensive cmpxchg() to set
up the memcg/objcgs pointer, because an allocation can race with a
different allocation on another cpu.

But in some common cases it's known for sure that a slab page will contain
accounted objects: if the page belongs to a slab cache with a SLAB_ACCOUNT
flag set.  It includes such popular objects like vm_area_struct, anon_vma,
task_struct, etc.

In such cases we can pre-allocate the objcgs vector and simple assign it
to the page without any atomic operations, because at this early stage the
page is not visible to anyone else.

A very simplistic benchmark (allocating 10000000 64-bytes objects in a
row) shows ~15% win.  In the real life it seems that most workloads are
not very sensitive to the speed of (accounted) slab allocations.

[guro@fb.com: open-code set_page_objcgs() and add some comments, by Johannes]
  Link: https://lkml.kernel.org/r/20201113001926.GA2934489@carbon.dhcp.thefacebook.com
[akpm@linux-foundation.org: fix it for mm-slub-call-account_slab_page-after-slab-page-initialization-fix.patch]

Link: https://lkml.kernel.org/r/20201110195753.530157-2-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Yu Zhao
cad8320b4b mm/swap: don't SetPageWorkingset unconditionally during swapin
We are capable of SetPageWorkingset based on refault distances after
commit aae466b005 ("mm/swap: implement workingset detection for
anonymous LRU").  This is done by workingset_refault(), which is right
above the unconditional SetPageWorkingset deleted by this patch.

The unconditional SetPageWorkingset miscategorizes pages that are read
ahead or never belonged to the working set (e.g., tmpfs pages accessed
only once by fd).  When those pages are swapped in (after they were
swapped out) for the first time, they skew PSI (when using async swap).
When this happens again, depending on their refault distances, they might
skew workingset_restore_anon counter in addition to PSI because their
shadows indicate they were part of the working set.

Historically, SetPageWorkingset was added as part of the PSI series, and
Johannes said:
 "It was meant to mark incoming pages under IO with SetPageWorkingset
  when waiting for them constituted a memory stall.

  On the page cache side, because we HAVE workingset detection, this was
  specific to recently evicted pages that had been active in their
  previous life. On the anon side, the aging algorithm had no
  distinction between workingset and sporadically used pages. Given the
  choice between a) no swapin stalls are pressure and b) all swapin
  stalls are pressure, I went with the latter in order to detect swap
  storms. The false positive case - high rate of swapin without severe
  memory pressure - was relatively unlikely, because we tried to avoid
  swapping until everything was completely on fire in the first place."

Link: https://lkml.kernel.org/r/20201209012400.1771150-1-yuzhao@google.com
Link: https://lkml.kernel.org/r/20201214231253.62313-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Rikard Falkeborn
e48333b660 mm/swap_state: constify static struct attribute_group
The only usage of swap_attr_group is to pass its address to
sysfs_create_group() which takes a pointer to const attribute_group.  Make
it const to allow the compiler to put it in read-only memory.

Link: https://lkml.kernel.org/r/20210201233254.91809-1-rikard.falkeborn@gmail.com
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Reviewed-by: Amy Parker <enbyamy@gmail.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Georgi Djakov
25eaab438d mm/page_io: use pr_alert_ratelimited for swap read/write errors
If there are errors during swap read or write, they can easily fill the
log buffer and remove any previous messages that might be useful for
debugging, especially on systems that rely for logging only on the kernel
ring-buffer.

For example, on a systems using zram as swap, we are more likely to see
any page allocation errors preceding the swap write errors if the alerts
are ratelimited.

Link: https://lkml.kernel.org/r/20210201142055.29068-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Stephen Zhang
cf532faa41 mm/swapfile.c: fix debugging information problem
Once the function name is changed, it may be easy to forget to modify the
corresponding code here.

Link: https://lkml.kernel.org/r/1611369120-2276-1-git-send-email-stephenzhangzsd@gmail.com
Signed-off-by: Stephen Zhang <stephenzhangzsd@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Yang Li
191a7221b7 mm/swap_slots.c: remove redundant NULL check
Fix below warnings reported by coccicheck:

  mm/swap_slots.c:197:3-9: WARNING: NULL check before some freeing functions is not needed.

Link: https://lkml.kernel.org/r/1611214229-11225-1-git-send-email-abaci-bugfix@linux.alibaba.com
Signed-off-by: Yang Li <abaci-bugfix@linux.alibaba.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Baolin Wang
6986c3e2b1 mm: backing-dev: Remove duplicated macro definition
Move the K() macro a little forward to remove the same macro definition.

Link: https://lkml.kernel.org/r/d1ccdf2d3116dce9814f2bcc1f0415ecb4c76ea5.1612862230.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Christoph Hellwig
826ea860bc mm/filemap: simplify generic_file_read_iter
Avoid the pointless goto out just for returning retval.

Link: https://lkml.kernel.org/r/20210122160140.223228-19-willy@infradead.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Christoph Hellwig
87fa0f3eb2 mm/filemap: rename generic_file_buffered_read to filemap_read
Rename generic_file_buffered_read to match the naming of filemap_fault,
also update the written parameter to a more descriptive name and improve
the kerneldoc comment.

Link: https://lkml.kernel.org/r/20210122160140.223228-18-willy@infradead.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
aa1ec2f697 mm/filemap: don't relock the page after calling readpage
We don't need to get the page lock again; we just need to wait for the I/O
to finish, so use wait_on_page_locked_killable() like the other callers of
->readpage.

Link: https://lkml.kernel.org/r/20210122160140.223228-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
2642fca647 mm/filemap: restructure filemap_get_pages
Remove the got_pages label, remove indentation, rename find_page to retry,
simplify error handling.

Link: https://lkml.kernel.org/r/20210122160140.223228-16-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
5963fe0316 mm/filemap: split filemap_readahead out of filemap_get_pages
This simplifies the error handling.

Link: https://lkml.kernel.org/r/20210122160140.223228-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
fce70da3a8 mm/filemap: add filemap_range_uptodate
Move the complicated condition and the calculations out of
filemap_update_page() into its own function.

[willy@infradead.org: unlock page before dropping its refcount]
  Link: https://lkml.kernel.org/r/20210201125229.GO308988@casper.infradead.org

Link: https://lkml.kernel.org/r/20210122160140.223228-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
87d1d7b688 mm/filemap: move the iocb checks into filemap_update_page
We don't need to give up when a non-blocking request sees a !Uptodate
page.  We may be able to satisfy the read from a partially-uptodate page.

Link: https://lkml.kernel.org/r/20210122160140.223228-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
4612aeef09 mm/filemap: convert filemap_update_page to return an errno
Use AOP_TRUNCATED_PAGE to indicate that no error occurred, but the page we
looked up is no longer valid.  In this case, the reference to the page
will have been removed; if we hit any other error, the caller will release
the reference.

Link: https://lkml.kernel.org/r/20210122160140.223228-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
f253e1854c mm/filemap: change filemap_create_page calling conventions
By moving the iocb flag checks to the caller, we can pass the file and the
page index instead of the iocb.  It never needed the iter.  By passing the
pagevec, we can return an errno (or AOP_TRUNCATED_PAGE) instead of an
ERR_PTR.

Link: https://lkml.kernel.org/r/20210122160140.223228-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
68430303c8 mm/filemap: change filemap_read_page calling conventions
Make this function more generic by passing the file instead of the iocb.
Check in the callers whether we should call readpage or not.  Also make it
return an errno / 0 / AOP_TRUNCATED_PAGE, and make calling put_page() the
caller's responsibility.

Link: https://lkml.kernel.org/r/20210122160140.223228-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
33a0f5c6b3 mm/filemap: don't call ->readpage if IOCB_WAITQ is set
The readpage operation can block in many (most?) filesystems, so we should
punt to a work queue instead of calling it.  This was the last caller of
lock_page_for_iocb(), so remove it.

Link: https://lkml.kernel.org/r/20210122160140.223228-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
f32b5dd721 mm/filemap: inline __wait_on_page_locked_async into caller
The previous patch removed wait_on_page_locked_async(), so inline
__wait_on_page_locked_async into __lock_page_async().

Link: https://lkml.kernel.org/r/20210122160140.223228-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
bd8a1f3655 mm/filemap: support readpage splitting a page
For page splitting to succeed, the thread asking to split the page has to
be the only one with a reference to the page.  Calling
wait_on_page_locked() while holding a reference to the page will
effectively prevent this from happening with sufficient threads waiting on
the same page.  Use put_and_wait_on_page_locked() to sleep without holding
a reference to the page, then retry the page lookup after the page is
unlocked.

Since we now get the page lock a little earlier in filemap_update_page(),
we can eliminate a number of duplicate checks.  The original intent
(commit ebded02788 ("avoid unnecessary calls to lock_page when waiting
for IO to complete during a read")) behind getting the page lock later was
to avoid re-locking the page after it has been brought uptodate by another
thread.  We still avoid that because we go through the normal lookup path
again after the winning thread has brought the page uptodate.

Link: https://lkml.kernel.org/r/20210122160140.223228-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
4805462598 mm/filemap: pass a sleep state to put_and_wait_on_page_locked
This is prep work for the next patch, but I think at least one of the
current callers would prefer a killable sleep to an uninterruptible one.

Link: https://lkml.kernel.org/r/20210122160140.223228-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:28 -08:00
Matthew Wilcox (Oracle)
cbd59c48ae mm/filemap: use head pages in generic_file_buffered_read
Add filemap_get_read_batch() which returns the head pages which represent
a contiguous array of bytes in the file.  It also stops when encountering
a page marked as Readahead or !Uptodate (but does return that page) so it
can be handled appropriately by filemap_get_pages().  That lets us remove
the loop in filemap_get_pages() and check only the last page.

Link: https://lkml.kernel.org/r/20210122160140.223228-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Matthew Wilcox (Oracle)
ff993ba130 mm/filemap: convert filemap_get_pages to take a pagevec
Using a pagevec lets us keep the pages and the number of pages together
which simplifies a lot of the calling conventions.

Link: https://lkml.kernel.org/r/20210122160140.223228-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Matthew Wilcox (Oracle)
0c7c575df5 mm/filemap: remove dynamically allocated array from filemap_read
Increasing the batch size runs into diminishing returns.  It's probably
better to make, eg, three calls to filemap_get_pages() than it is to call
into kmalloc().

Link: https://lkml.kernel.org/r/20210122160140.223228-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Matthew Wilcox (Oracle)
3a6bae4839 mm/filemap: rename generic_file_buffered_read subfunctions
Patch series "Refactor generic_file_buffered_read", v5.

This is a combination of Christoph's work to refactor
generic_file_buffered_read() and some of my large-page support
which was disrupted by Kent's refactoring of generic_file_buffered_read.

This patch (of 18):

The recent split of generic_file_buffered_read() created some very long
function names which are hard to distinguish from each other.  Rename as
follows:

generic_file_buffered_read_readpage -> filemap_read_page
generic_file_buffered_read_pagenotuptodate -> filemap_update_page
generic_file_buffered_read_no_cached_page -> filemap_create_page
generic_file_buffered_read_get_pages -> filemap_get_pages

Link: https://lkml.kernel.org/r/20210122160140.223228-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20210122160140.223228-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Pavel Begunkov
ab2125df92 mm/filemap: don't revert iter on -EIOCBQUEUED
Currently, if I/O is enqueued for async execution direct paths of
generic_file_{read,write}_iter() will always revert the iter.  There are
no users expecting that, and that is also costly.  Leave iterators as is
on -EIOCBQUEUED.

Link: https://lkml.kernel.org/r/f5247b60e7abbd2ff850cd108491f53a2e0c501a.1610207781.git.asml.silence@gmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Baolin Wang
1f7ef65774 mm/filemap: remove unused parameter and change to void type for replace_page_cache_page()
Since commit 74d609585d ("page cache: Add and replace pages using the
XArray") was merged, the replace_page_cache_page() can not fail and always
return 0, we can remove the redundant return value and void it.  Moreover
remove the unused gfp_mask.

Link: https://lkml.kernel.org/r/609c30e5274ba15d8b90c872fd0d8ac437a9b2bb.1610071401.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Miaohe Lin
1d2cae8ea1 mm/page_owner: use helper function zone_end_pfn() to get end_pfn
Commit 108bcc96ef ("mm: add & use zone_end_pfn() and zone_spans_pfn()")
introduced the helper zone_end_pfn() to calculate the zone end pfn.  But
pagetypeinfo_showmixedcount_print forgot to use it.  And the
initialization of local variable pfn is duplicated, remove one.

Link: https://lkml.kernel.org/r/20210123070538.5861-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Anshuman Khandual
2e326c07bb mm/debug_vm_pgtable/basic: iterate over entire protection_map[]
Currently the basic tests just validate various page table transformations
after starting with vm_get_page_prot(VM_READ|VM_WRITE|VM_EXEC) protection.
Instead scan over the entire protection_map[] for better coverage.  It
also makes sure that all these basic page table tranformations checks hold
true irrespective of the starting protection value for the page table
entry.  There is also a slight change in the debug print format for basic
tests to capture the protection value it is being tested with.  The
modified output looks something like

[pte_basic_tests          ]: Validating PTE basic ()
[pte_basic_tests          ]: Validating PTE basic (read)
[pte_basic_tests          ]: Validating PTE basic (write)
[pte_basic_tests          ]: Validating PTE basic (read|write)
[pte_basic_tests          ]: Validating PTE basic (exec)
[pte_basic_tests          ]: Validating PTE basic (read|exec)
[pte_basic_tests          ]: Validating PTE basic (write|exec)
[pte_basic_tests          ]: Validating PTE basic (read|write|exec)
[pte_basic_tests          ]: Validating PTE basic (shared)
[pte_basic_tests          ]: Validating PTE basic (read|shared)
[pte_basic_tests          ]: Validating PTE basic (write|shared)
[pte_basic_tests          ]: Validating PTE basic (read|write|shared)
[pte_basic_tests          ]: Validating PTE basic (exec|shared)
[pte_basic_tests          ]: Validating PTE basic (read|exec|shared)
[pte_basic_tests          ]: Validating PTE basic (write|exec|shared)
[pte_basic_tests          ]: Validating PTE basic (read|write|exec|shared)

This adds a missing argument 'struct mm_struct *' in pud_basic_tests()
test .  This never got exposed before as PUD based THP is available only
on X86 platform where mm_pmd_folded(mm) call gets macro replaced without
requiring the mm_struct i.e __is_defined(__PAGETABLE_PMD_FOLDED).

Link: https://lkml.kernel.org/r/1611137241-26220-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Reviewed-by: Steven Price <steven.price@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Anshuman Khandual
bb5c47ced4 mm/debug_vm_pgtable/basic: add validation for dirtiness after write protect
Patch series "mm/debug_vm_pgtable: Some minor updates", v3.

This series contains some cleanups and new test suggestions from Catalin
from an earlier discussion.

https://lore.kernel.org/linux-mm/20201123142237.GF17833@gaia/

This patch (of 2):

This adds validation tests for dirtiness after write protect conversion
for each page table level.  There are two new separate test types involved
here.

The first test ensures that a given page table entry does not become dirty
after pxx_wrprotect().  This is important for platforms like arm64 which
transfers and drops the hardware dirty bit (!PTE_RDONLY) to the software
dirty bit while making it an write protected one.  This test ensures that
no fresh page table entry could be created with hardware dirty bit set.
The second test ensures that a given page table entry always preserve the
dirty information across pxx_wrprotect().

This adds two previously missing PUD level basic tests and while here
fixes pxx_wrprotect() related typos in the documentation file.

Link: https://lkml.kernel.org/r/1611137241-26220-1-git-send-email-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/1611137241-26220-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Matthew Wilcox (Oracle)
91f5345afb mm/debug: improve memcg debugging
The memcg_data is only valid on the head page, not the tail pages.  Change
the format and location of the printout within the dump to match the other
parts of struct page better.

Link: https://lkml.kernel.org/r/20210114190200.1894484-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Zhiyuan Dai
457c82c351 mm/slub: minor coding style tweaks
Add whitespace to fix coding style issues, improve code reading.

Link: https://lkml.kernel.org/r/1612847403-5594-1-git-send-email-daizhiyuan@phytium.com.cn
Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Vlastimil Babka
fe2cce15d6 mm, slub: remove slub_memcg_sysfs boot param and CONFIG_SLUB_MEMCG_SYSFS_ON
The boot param and config determine the value of memcg_sysfs_enabled,
which is unused since commit 10befea91b ("mm: memcg/slab: use a single
set of kmem_caches for all allocations") as there are no per-memcg kmem
caches anymore.

Link: https://lkml.kernel.org/r/20210127124745.7928-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
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>
2021-02-24 13:38:27 -08:00