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qubes-linux-kernel/patches.suse/SoN-33-slab-leak-fix.patch

46 lines
1.4 KiB

From: Nick Piggin <npiggin@suse.de>
Subject: Fix almost-infinite slab cache growing
References: bnc#554081
Patch-mainline: never
If we get into cache_alloc_refill() with must_refill set, we end up in an
almost endless loop adding more and more pages to the slab. The loop can be
broken only by a failure to allocate more pages or an interrupt refilling the
slab's allocation cache.
Fix the issue by jumping to a more appropriate place when the allocation cache
is not refilled by an interrupt.
Signed-off-by: Nick Piggin <npiggin@suse.de
Acked-by: Jan Kara <jack@suse.cz>
Index: linux-2.6.38-master/mm/slab.c
===================================================================
--- linux-2.6.38-master.orig/mm/slab.c
+++ linux-2.6.38-master/mm/slab.c
@@ -3104,11 +3104,11 @@ static void *cache_alloc_refill(struct k
struct array_cache *ac;
int node;
-retry:
check_irq_off();
node = numa_slab_nid(cachep, flags);
if (unlikely(must_refill))
goto force_grow;
+retry:
ac = cpu_cache_get(cachep);
batchcount = ac->batchcount;
if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
@@ -3188,8 +3188,10 @@ force_grow:
if (!x && (ac->avail == 0 || must_refill))
return NULL;
- if (!ac->avail) /* objects refilled by interrupt? */
+ if (!ac->avail) { /* objects refilled by interrupt? */
+ node = numa_node_id();
goto retry;
+ }
}
ac->touched = 1;
return ac->entry[--ac->avail];