mm/slub: fix bulk alloc and free stats

The SLUB sysfs stats enabled CONFIG_SLUB_STATS have two deficiencies
identified wrt bulk alloc/free operations:

- Bulk allocations from cpu freelist are not counted. Add the
  ALLOC_FASTPATH counter there.

- Bulk fastpath freeing will count a list of multiple objects with a
  single FREE_FASTPATH inc. Add a stat_add() variant to count them all.

Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slub.c b/mm/slub.c
index 3f8b957571068c83445af31fe29ce316a7a50d3b..d7b0ca6012e02a1c60d1eecd493ba293a0c524ca 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -396,6 +396,14 @@ static inline void stat(const struct kmem_cache *s, enum stat_item si)
 #endif
 }
 
+static inline
+void stat_add(const struct kmem_cache *s, enum stat_item si, int v)
+{
+#ifdef CONFIG_SLUB_STATS
+       raw_cpu_add(s->cpu_slab->stat[si], v);
+#endif
+}
+
 /*
  * The slab lists for all objects.
  */
@@ -4268,7 +4276,7 @@ redo:
 
                local_unlock(&s->cpu_slab->lock);
        }
-       stat(s, FREE_FASTPATH);
+       stat_add(s, FREE_FASTPATH, cnt);
 }
 #else /* CONFIG_SLUB_TINY */
 static void do_slab_free(struct kmem_cache *s,
@@ -4545,6 +4553,7 @@ static inline int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
                c->freelist = get_freepointer(s, object);
                p[i] = object;
                maybe_wipe_obj_freeptr(s, p[i]);
+               stat(s, ALLOC_FASTPATH);
        }
        c->tid = next_tid(c->tid);
        local_unlock_irqrestore(&s->cpu_slab->lock, irqflags);