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authorDave Hansen <dave.hansen@linux.intel.com>2014-01-24 07:20:23 -0800
committerPekka Enberg <penberg@kernel.org>2014-01-31 13:41:26 +0200
commit67b6c900dc6dce65478d6fe37b60cd1e65bb80c2 (patch)
treec6c1b99a3483cd94481d72a35d16fe4243c329cc
parent433a91ff5fa19e3eb70b12f7056f234aebd09ac2 (diff)
downloadop-kernel-dev-67b6c900dc6dce65478d6fe37b60cd1e65bb80c2.zip
op-kernel-dev-67b6c900dc6dce65478d6fe37b60cd1e65bb80c2.tar.gz
mm: slub: work around unneeded lockdep warning
The slub code does some setup during early boot in early_kmem_cache_node_alloc() with some local data. There is no possible way that another CPU can see this data, so the slub code doesn't unnecessarily lock it. However, some new lockdep asserts check to make sure that add_partial() _always_ has the list_lock held. Just add the locking, even though it is technically unnecessary. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
-rw-r--r--mm/slub.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/slub.c b/mm/slub.c
index a99e9e6..432bddf 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2890,7 +2890,13 @@ static void early_kmem_cache_node_alloc(int node)
init_kmem_cache_node(n);
inc_slabs_node(kmem_cache_node, node, page->objects);
+ /*
+ * the lock is for lockdep's sake, not for any actual
+ * race protection
+ */
+ spin_lock(&n->list_lock);
add_partial(n, page, DEACTIVATE_TO_HEAD);
+ spin_unlock(&n->list_lock);
}
static void free_kmem_cache_nodes(struct kmem_cache *s)
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