Commit 51cd8e6f authored Aug 28, 2012 by David Rientjes Committed by Linus Torvalds Aug 29, 2012

mm, slab: lock the correct nodelist after reenabling irqs



cache_grow() can reenable irqs so the cpu (and node) can change, so ensure
that we take list_lock on the correct nodelist.

This fixes an issue with commit 072bb0aa ("mm: sl[au]b: add
knowledge of PFMEMALLOC reserve pages") where list_lock for the wrong
node was taken after growing the cache.

Reported-and-tested-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c182ae42

mm/slab.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -3260,6 +3260,7 @@ force_grow:

	/* cache_grow can reenable interrupts, then ac could change. */		/* cache_grow can reenable interrupts, then ac could change. */
	ac = cpu_cache_get(cachep);		ac = cpu_cache_get(cachep);
			node = numa_mem_id();

	/* no objects in sight? abort */		/* no objects in sight? abort */
	if (!x && (ac->avail == 0 \|\| force_refill))		if (!x && (ac->avail == 0 \|\| force_refill))

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