slub: Add statistics for this_cmpxchg_double failures
Add some statistics for debugging.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 90fbb6d..45ca123 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -32,6 +32,7 @@
DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
ORDER_FALLBACK, /* Number of times fallback was necessary */
+ CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
NR_SLUB_STAT_ITEMS };
struct kmem_cache_cpu {
diff --git a/mm/slub.c b/mm/slub.c
index e126cfb..93de30d 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -217,7 +217,7 @@
#endif
-static inline void stat(struct kmem_cache *s, enum stat_item si)
+static inline void stat(const struct kmem_cache *s, enum stat_item si)
{
#ifdef CONFIG_SLUB_STATS
__this_cpu_inc(s->cpu_slab->stat[si]);
@@ -1597,6 +1597,7 @@
printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
actual_tid, tid, next_tid(tid));
#endif
+ stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
}
#endif