2022-04-29 13:43:40

by Miaohe Lin

Subject: [PATCH 1/9] mm/z3fold: fix sheduling while atomic

z3fold's page_lock is always held when calling alloc_slots. So gfp should
be GFP_ATOMIC to avoid "scheduling while atomic" bug.

Fixes: fc5488651c7d ("z3fold: simplify freeing slots")
Signed-off-by: Miaohe Lin <[email protected]>
---
mm/z3fold.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/z3fold.c b/mm/z3fold.c
index 83b5a3514427..c2260f5a5885 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -941,8 +941,7 @@ static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool,
}

if (zhdr && !zhdr->slots)
- zhdr->slots = alloc_slots(pool,
- can_sleep ? GFP_NOIO : GFP_ATOMIC);
+ zhdr->slots = alloc_slots(pool, GFP_ATOMIC);
return zhdr;
}

--
2.23.0

2022-05-19 11:00:00

by Vitaly Wool

Subject: Re: [PATCH 1/9] mm/z3fold: fix sheduling while atomic

On Fri, Apr 29, 2022 at 8:40 AM Miaohe Lin <[email protected]> wrote:
>
> z3fold's page_lock is always held when calling alloc_slots. So gfp should
> be GFP_ATOMIC to avoid "scheduling while atomic" bug.
>
> Fixes: fc5488651c7d ("z3fold: simplify freeing slots")
> Signed-off-by: Miaohe Lin <[email protected]>
> ---
> mm/z3fold.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index 83b5a3514427..c2260f5a5885 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -941,8 +941,7 @@ static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool,
> }
>
> if (zhdr && !zhdr->slots)
> - zhdr->slots = alloc_slots(pool,
> - can_sleep ? GFP_NOIO : GFP_ATOMIC);
> + zhdr->slots = alloc_slots(pool, GFP_ATOMIC);
> return zhdr;
> }

Reviewed-by: Vitaly Wool <[email protected]>
> --
> 2.23.0
>