Skip to content

Commit

Permalink
mm/slab: do not change cache size if debug pagealloc isn't possible
Browse files Browse the repository at this point in the history
We can fail to setup off slab in some conditions.  Even in this case,
debug pagealloc increases cache size to PAGE_SIZE in advance and it is
waste because debug pagealloc cannot work for it when it isn't the off
slab.  To improve this situation, this patch checks first that this
cache with increased size is suitable for off slab.  It actually
increases cache size when it is suitable for off-slab, so possible waste
is removed.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  • Loading branch information
Joonsoo Kim authored and Linus Torvalds committed Mar 15, 2016
1 parent 158e319 commit f3a3c32
Showing 1 changed file with 11 additions and 4 deletions.
15 changes: 11 additions & 4 deletions mm/slab.c
Original file line number Diff line number Diff line change
Expand Up @@ -2206,10 +2206,17 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
*/
if (debug_pagealloc_enabled() && (flags & SLAB_POISON) &&
!slab_early_init && size >= kmalloc_size(INDEX_NODE) &&
size >= 256 && cachep->object_size > cache_line_size() &&
size < PAGE_SIZE) {
cachep->obj_offset += PAGE_SIZE - size;
size = PAGE_SIZE;
size >= 256 && cachep->object_size > cache_line_size()) {
if (size < PAGE_SIZE || size % PAGE_SIZE == 0) {
size_t tmp_size = ALIGN(size, PAGE_SIZE);

if (set_off_slab_cache(cachep, tmp_size, flags)) {
flags |= CFLGS_OFF_SLAB;
cachep->obj_offset += tmp_size - size;
size = tmp_size;
goto done;
}
}
}
#endif

Expand Down

0 comments on commit f3a3c32

Please sign in to comment.