]> www.infradead.org Git - users/jedix/linux-maple.git/commit
mm, slub: consider rest of partial list if acquire_slab() fails
authorJann Horn <jannh@google.com>
Thu, 31 Dec 2020 22:03:51 +0000 (22:03 +0000)
committerJohannes Weiner <hannes@cmpxchg.org>
Thu, 31 Dec 2020 22:03:51 +0000 (22:03 +0000)
commit12042b12203ab133b2d2ba2ee0a95add230d7e03
treea8dba0b8db79e8f16bf81ad38aada95595963658
parente076ef132508d845da9f615a08aec4b45cd7ef1b
mm, slub: consider rest of partial list if acquire_slab() fails

acquire_slab() fails if there is contention on the freelist of the page
(probably because some other CPU is concurrently freeing an object from
the page).  In that case, it might make sense to look for a different page
(since there might be more remote frees to the page from other CPUs, and
we don't want contention on struct page).

However, the current code accidentally stops looking at the partial list
completely in that case.  Especially on kernels without CONFIG_NUMA set,
this means that get_partial() fails and new_slab_objects() falls back to
new_slab(), allocating new pages.  This could lead to an unnecessary
increase in memory fragmentation.

Link: https://lkml.kernel.org/r/20201228130853.1871516-1-jannh@google.com
Fixes: 7ced37197196 ("slub: Acquire_slab() avoid loop")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/slub.c