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

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Message-ID: <c2e28e27-d84b-4671-8784-de5fe0d14f41@lucifer.local>
Date: Wed, 17 Sep 2025 06:13:40 +0100
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: Chris Mason <clm@...a.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
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Subject: Re: [PATCH 02/10] mm: convert core mm to mm_flags_*() accessors

On Tue, Sep 16, 2025 at 12:49:13PM -0700, Chris Mason wrote:
> 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.

Thanks, my bad, will send a fix-patch.

Kind of remarkable/interesting nothing hit this though... but not necessarily a
good thing :)

>
> -chris
>

Cheers, Lorenzo