Commit 8f58119a authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Linus Torvalds

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.
Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarRoman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Jann Horn <jannh@google.com>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20200610163135.17364-6-vbabka@suse.czSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 060807f8
...@@ -5207,16 +5207,7 @@ static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) ...@@ -5207,16 +5207,7 @@ static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
{ {
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
} }
SLAB_ATTR_RO(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);
static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
{ {
......
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