slub: do not merge cache if slub_debug contains a never-merge flag

In case CONFIG_SLUB_DEBUG_ON=n, find_mergeable() gets debug features from
commandline but never checks if there are features from the
SLAB_NEVER_MERGE set.

As a result selected by slub_debug caches are always mergeable if they
have been created without a custom constructor set or without one of the
SLAB_* debug features on.

This moves the SLAB_NEVER_MERGE check below the flags update from
commandline to make sure it won't merge the slab cache if one of the debug
features is on.

Link: http://lkml.kernel.org/r/20170101124451.GA4740@lp-laptop-d
Signed-off-by: Grygorii Maistrenko <grygoriimkd@gmail.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
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>
This commit is contained in:
Grygorii Maistrenko 2017-02-22 15:40:59 -08:00 committed by Linus Torvalds
parent 8dcde9def5
commit c6e28895a4
1 changed files with 4 additions and 1 deletions

View File

@ -255,7 +255,7 @@ struct kmem_cache *find_mergeable(size_t size, size_t align,
{ {
struct kmem_cache *s; struct kmem_cache *s;
if (slab_nomerge || (flags & SLAB_NEVER_MERGE)) if (slab_nomerge)
return NULL; return NULL;
if (ctor) if (ctor)
@ -266,6 +266,9 @@ struct kmem_cache *find_mergeable(size_t size, size_t align,
size = ALIGN(size, align); size = ALIGN(size, align);
flags = kmem_cache_flags(size, flags, name, NULL); flags = kmem_cache_flags(size, flags, name, NULL);
if (flags & SLAB_NEVER_MERGE)
return NULL;
list_for_each_entry_reverse(s, &slab_caches, list) { list_for_each_entry_reverse(s, &slab_caches, list) {
if (slab_unmergeable(s)) if (slab_unmergeable(s))
continue; continue;