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authorJann Horn <jannh@google.com>2021-01-12 15:49:04 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-19 18:26:18 +0100
commitc2226680343da071279788624aa6e59479b25e2f (patch)
tree3d25fe36c94812e7fab4ef7e4d87f5fd1f82d0b3 /mm
parentdrm/i915/dsi: Use unconditional msleep for the panel_on_delay when there is no reset-deassert MIPI-sequence (diff)
downloadwireguard-linux-c2226680343da071279788624aa6e59479b25e2f.tar.xz
wireguard-linux-c2226680343da071279788624aa6e59479b25e2f.zip
mm, slub: consider rest of partial list if acquire_slab() fails
commit 8ff60eb052eeba95cfb3efe16b08c9199f8121cf upstream. 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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slub.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c
index f41414571c9e..8b3ef45a0f10 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1887,7 +1887,7 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
t = acquire_slab(s, n, page, object == NULL, &objects);
if (!t)
- break;
+ continue; /* cmpxchg raced */
available += objects;
if (!object) {