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authorRoman Gushchin <roman.gushchin@linux.dev>2023-11-07 18:18:02 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-11-16 00:30:09 +0100
commit24948e3b7b12e0031a6edb4f49bbb9fb2ad1e4e9 (patch)
treeab944477ea3ea6fdcd1a0a88ff00c80e2082b5af
parentmm/damon/sysfs-schemes: handle tried region directory allocation failure (diff)
downloadlinux-24948e3b7b12e0031a6edb4f49bbb9fb2ad1e4e9.tar.xz
linux-24948e3b7b12e0031a6edb4f49bbb9fb2ad1e4e9.zip
mm: kmem: drop __GFP_NOFAIL when allocating objcg vectors
Objcg vectors attached to slab pages to store slab object ownership information are allocated using gfp flags for the original slab allocation. Depending on slab page order and the size of slab objects, objcg vector can take several pages. If the original allocation was done with the __GFP_NOFAIL flag, it triggered a warning in the page allocation code. Indeed, order > 1 pages should not been allocated with the __GFP_NOFAIL flag. Fix this by simply dropping the __GFP_NOFAIL flag when allocating the objcg vector. It effectively allows to skip the accounting of a single slab object under a heavy memory pressure. An alternative would be to implement the mechanism to fallback to order-0 allocations for accounting metadata, which is also not perfect because it will increase performance penalty and memory footprint of the kernel memory accounting under memory pressure. Link: https://lkml.kernel.org/r/ZUp8ZFGxwmCx4ZFr@P9FQF9L96D.corp.robot.car Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reported-by: Christoph Lameter <cl@linux.com> Closes: https://lkml.kernel.org/r/6b42243e-f197-600a-5d22-56bd728a5ad8@gentwo.org Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/memcontrol.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 774bd6e21e27..1c1061df9cd1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2936,7 +2936,8 @@ void mem_cgroup_commit_charge(struct folio *folio, struct mem_cgroup *memcg)
* Moreover, it should not come from DMA buffer and is not readily
* reclaimable. So those GFP bits should be masked off.
*/
-#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT)
+#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | \
+ __GFP_ACCOUNT | __GFP_NOFAIL)
/*
* mod_objcg_mlstate() may be called with irq enabled, so