* [PATCH] mm/slub: mark racy access on slab->freelist
@ 2024-04-27 8:51 linke li
2024-04-28 8:10 ` David Rientjes
2024-05-02 12:23 ` Vlastimil Babka
0 siblings, 2 replies; 4+ messages in thread
From: linke li @ 2024-04-27 8:51 UTC (permalink / raw)
Cc: xujianhao01, linke li, Christoph Lameter, Pekka Enberg,
David Rientjes, Joonsoo Kim, Andrew Morton, Vlastimil Babka,
Roman Gushchin, Hyeonggon Yoo, linux-mm, linux-kernel
In deactivate_slab(), slab->freelist can be changed concurrently. Mark
data race on slab->freelist as benign using READ_ONCE.
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>
---
mm/slub.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/slub.c b/mm/slub.c
index 0d700f6ca547..bb0e05a321e9 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2813,7 +2813,7 @@ static void deactivate_slab(struct kmem_cache *s, struct slab *slab,
struct slab new;
struct slab old;
- if (slab->freelist) {
+ if (READ_ONCE(slab->freelist)) {
stat(s, DEACTIVATE_REMOTE_FREES);
tail = DEACTIVATE_TO_TAIL;
}
--
2.39.3 (Apple Git-146)
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] mm/slub: mark racy access on slab->freelist
2024-04-27 8:51 [PATCH] mm/slub: mark racy access on slab->freelist linke li
@ 2024-04-28 8:10 ` David Rientjes
2024-04-29 2:25 ` linke li
2024-05-02 12:23 ` Vlastimil Babka
1 sibling, 1 reply; 4+ messages in thread
From: David Rientjes @ 2024-04-28 8:10 UTC (permalink / raw)
To: linke li
Cc: xujianhao01, Christoph Lameter, Pekka Enberg, Joonsoo Kim,
Andrew Morton, Vlastimil Babka, Roman Gushchin, Hyeonggon Yoo,
linux-mm, linux-kernel
On Sat, 27 Apr 2024, linke li wrote:
> In deactivate_slab(), slab->freelist can be changed concurrently. Mark
> data race on slab->freelist as benign using READ_ONCE.
>
> This patch is aimed at reducing the number of benign races reported by
> KCSAN in order to focus future debugging effort on harmful races.
>
Thanks! Do you have a data race report to copy+paste into the commit
description so people can search for it if they stumble across the same
thing?
> Signed-off-by: linke li <lilinke99@qq.com>
> ---
> mm/slub.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 0d700f6ca547..bb0e05a321e9 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2813,7 +2813,7 @@ static void deactivate_slab(struct kmem_cache *s, struct slab *slab,
> struct slab new;
> struct slab old;
>
> - if (slab->freelist) {
> + if (READ_ONCE(slab->freelist)) {
> stat(s, DEACTIVATE_REMOTE_FREES);
> tail = DEACTIVATE_TO_TAIL;
> }
> --
> 2.39.3 (Apple Git-146)
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mm/slub: mark racy access on slab->freelist
2024-04-28 8:10 ` David Rientjes
@ 2024-04-29 2:25 ` linke li
0 siblings, 0 replies; 4+ messages in thread
From: linke li @ 2024-04-29 2:25 UTC (permalink / raw)
To: rientjes
Cc: 42.hyeyoo, akpm, cl, iamjoonsoo.kim, lilinke99, linux-kernel,
linux-mm, penberg, roman.gushchin, vbabka, xujianhao01
> Thanks! Do you have a data race report to copy+paste into the commit
> description so people can search for it if they stumble across the same
> thing?
I don't have a data race report, just try to analyze the code statically
and then check it manually. I hope I could help in some way.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/slub: mark racy access on slab->freelist
2024-04-27 8:51 [PATCH] mm/slub: mark racy access on slab->freelist linke li
2024-04-28 8:10 ` David Rientjes
@ 2024-05-02 12:23 ` Vlastimil Babka
1 sibling, 0 replies; 4+ messages in thread
From: Vlastimil Babka @ 2024-05-02 12:23 UTC (permalink / raw)
To: linke li
Cc: xujianhao01, Christoph Lameter, Pekka Enberg, David Rientjes,
Joonsoo Kim, Andrew Morton, Roman Gushchin, Hyeonggon Yoo,
linux-mm, linux-kernel
On 4/27/24 10:51, linke li wrote:
> In deactivate_slab(), slab->freelist can be changed concurrently. Mark
> data race on slab->freelist as benign using READ_ONCE.
>
> 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>
Added to slab/for-6.10, thanks
> ---
> mm/slub.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 0d700f6ca547..bb0e05a321e9 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2813,7 +2813,7 @@ static void deactivate_slab(struct kmem_cache *s, struct slab *slab,
> struct slab new;
> struct slab old;
>
> - if (slab->freelist) {
> + if (READ_ONCE(slab->freelist)) {
> stat(s, DEACTIVATE_REMOTE_FREES);
> tail = DEACTIVATE_TO_TAIL;
> }
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-05-02 12:23 UTC | newest]
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2024-04-27 8:51 [PATCH] mm/slub: mark racy access on slab->freelist linke li
2024-04-28 8:10 ` David Rientjes
2024-04-29 2:25 ` linke li
2024-05-02 12:23 ` Vlastimil Babka
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