linux-kernel - Re: [PATCH 02/10] mm: convert core mm to mm_flags

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Message-ID: <20250916194915.1395712-1-clm@meta.com>
Date: Tue, 16 Sep 2025 12:49:13 -0700
From: Chris Mason <clm@...a.com>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
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Subject: Re: [PATCH 02/10] mm: convert core mm to mm_flags_*() accessors

On Tue, 12 Aug 2025 16:44:11 +0100 Lorenzo Stoakes <lorenzo.stoakes@...cle.com> wrote:

> As part of the effort to move to mm->flags becoming a bitmap field, convert
> existing users to making use of the mm_flags_*() accessors which will, when
> the conversion is complete, be the only means of accessing mm_struct flags.
> 
> This will result in the debug output being that of a bitmap output, which
> will result in a minor change here, but since this is for debug only, this
> should have no bearing.
> 
> Otherwise, no functional changes intended.
> 
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>

[ ... ]

> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 25923cfec9c6..17650f0b516e 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c

[ ... ]

> @@ -1251,7 +1251,7 @@ SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
>  	 * Check MMF_OOM_SKIP again under mmap_read_lock protection to ensure
>  	 * possible change in exit_mmap is seen
>  	 */
> -	if (!test_bit(MMF_OOM_SKIP, &mm->flags) && !__oom_reap_task_mm(mm))
> +	if (mm_flags_test(MMF_OOM_SKIP, mm) && !__oom_reap_task_mm(mm))
>  		ret = -EAGAIN;
>  	mmap_read_unlock(mm);
>  

Hi Lorzeno, I think we lost a ! here.

claude found enough inverted logic in moved code that I did a new run with
a more explicit prompt for it, but this was the only new hit.

-chris