The patch titled
Subject: mm, slub: make reclaim_account attribute read-only
has been added to the -mm tree. Its filename is
mm-slub-make-reclaim_account-attribute-read-only.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-slub-make-reclaim_account-attribute-read-only.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-slub-make-reclaim_account-attribute-read-only.patch
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------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm, slub: make reclaim_account attribute read-only
The attribute reflects the SLAB_RECLAIM_ACCOUNT cache flag. It's not
clear why this attribute was writable in the first place, as it's tied to
how the cache is used by its creator, it's not a user tunable.
Furthermore:
- it affects slab merging, but that's not being checked while toggled
- if affects whether __GFP_RECLAIMABLE flag is used to allocate page, but
the runtime toggle doesn't update allocflags
- it affects cache_vmstat_idx() so runtime toggling might lead to incosistency
of NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE
Thus make it read-only.
Link: http://lkml.kernel.org/r/20200610163135.17364-6-vbabka@xxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Roman Gushchin <guro@xxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
--- a/mm/slub.c~mm-slub-make-reclaim_account-attribute-read-only
+++ a/mm/slub.c
@@ -5223,16 +5223,7 @@ static ssize_t reclaim_account_show(stru
{
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
}
-
-static ssize_t reclaim_account_store(struct kmem_cache *s,
- const char *buf, size_t length)
-{
- s->flags &= ~SLAB_RECLAIM_ACCOUNT;
- if (buf[0] == '1')
- s->flags |= SLAB_RECLAIM_ACCOUNT;
- return length;
-}
-SLAB_ATTR(reclaim_account);
+SLAB_ATTR_RO(reclaim_account);
static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
{
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
mm-slub-extend-slub_debug-syntax-for-multiple-blocks.patch
mm-slub-make-some-slub_debug-related-attributes-read-only.patch
mm-slub-remove-runtime-allocation-order-changes.patch
mm-slub-make-remaining-slub_debug-related-attributes-read-only.patch
mm-slub-make-reclaim_account-attribute-read-only.patch
mm-slub-introduce-static-key-for-slub_debug.patch
mm-slub-introduce-kmem_cache_debug_flags.patch
mm-slub-extend-checks-guarded-by-slub_debug-static-key.patch
mm-slab-slub-move-and-improve-cache_from_obj.patch
