Re: [PATCH v2] mm,page_owner: don't remove __GFP_NOLOCKDEP in add_stack_record_to_list

[Vlastimil Babka <vbabka@suse.cz>]

On 4/29/24 10:28 AM, Christoph Hellwig wrote:
> Otherwise we'll generate false lockdep positives.
> 
> Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count")
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

> ---
> 
> Changes since v1:
>  - only pass on __GFP_NOLOCKDEP and leave the other masking in place
> 
>  mm/page_owner.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/page_owner.c b/mm/page_owner.c
> index d17d1351ec84af..428c1ea8b4579e 100644
> --- a/mm/page_owner.c
> +++ b/mm/page_owner.c
> @@ -170,7 +170,7 @@ static void add_stack_record_to_list(struct stack_record *stack_record,
>  
>  	/* Filter gfp_mask the same way stackdepot does, for consistency */
>  	gfp_mask &= ~GFP_ZONEMASK;
> -	gfp_mask &= (GFP_ATOMIC | GFP_KERNEL);
> +	gfp_mask &= (GFP_ATOMIC | GFP_KERNEL | __GFP_NOLOCKDEP);
>  	gfp_mask |= __GFP_NOWARN;
>  
>  	set_current_in_page_owner();