diff options
| author | linke li | 2024-03-21 11:48:15 +0800 |
|---|---|---|
| committer | Vlastimil Babka | 2024-03-25 09:45:28 +0100 |
| commit | 87654cf7a9865c0be256d67229b7354125d7498e (patch) | |
| tree | b5413ac2efb4a09d3cd29946afe35863fcdad6c8 /mm/slub.c | |
| parent | ad7c5ebead13323ac4a45e01bda0609629523076 (diff) | |
mm/slub: mark racy accesses on slab->slabs
The reads of slab->slabs are racy because it may be changed by
put_cpu_partial concurrently. In slabs_cpu_partial_show() and
show_slab_objects(), slab->slabs is only used for showing information.
Data-racy reads from shared variables that are used only for diagnostic
purposes should typically use data_race(), since it is normally not a
problem if the values are off by a little.
This patch is aimed at reducing the number of benign races reported by
KCSAN in order to focus future debugging effort on harmful races.
Signed-off-by: linke li <lilinke99@qq.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/slub.c b/mm/slub.c index cc7e68fbdbba..d35d91877625 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -6036,7 +6036,7 @@ static ssize_t show_slab_objects(struct kmem_cache *s, else if (flags & SO_OBJECTS) WARN_ON_ONCE(1); else - x = slab->slabs; + x = data_race(slab->slabs); total += x; nodes[node] += x; } @@ -6241,7 +6241,7 @@ static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf) slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu)); if (slab) - slabs += slab->slabs; + slabs += data_race(slab->slabs); } #endif @@ -6255,7 +6255,7 @@ static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf) slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu)); if (slab) { - slabs = READ_ONCE(slab->slabs); + slabs = data_race(slab->slabs); objects = (slabs * oo_objects(s->oo)) / 2; len += sysfs_emit_at(buf, len, " C%d=%d(%d)", cpu, objects, slabs); |