From: Peter Zijlstra <peterz@infradead.org>
To: Jiri Slaby <jirislaby@kernel.org>
Cc: Thomas Gleixner <tglx@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Matthieu Baerts <matttbe@kernel.org>
Subject: Re: [patch 1/4] sched/mmcid: Prevent CID stalls due to concurrent forks
Date: Wed, 11 Mar 2026 08:49:45 +0100 [thread overview]
Message-ID: <20260311074945.GJ606826@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <470f5363-8c84-4061-b8c3-4287d11ea6c3@kernel.org>
On Wed, Mar 11, 2026 at 08:33:01AM +0100, Jiri Slaby wrote:
> Thomas,
>
> On 10. 03. 26, 21:28, Thomas Gleixner wrote:
> > A newly forked task is accounted as MMCID user before the task is visible
> > in the process' thread list and the global task list. This creates the
> > following problem:
> ...
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -4729,8 +4729,12 @@ void sched_cancel_fork(struct task_struc
> > scx_cancel_fork(p);
> > }
> > +static void sched_mm_cid_fork(struct task_struct *t);
>
> This introduces:
> [ 97s] ../kernel/sched/core.c:4711:13: warning: ‘sched_mm_cid_fork’
> used but never defined
> [ 97s] 4711 | static void sched_mm_cid_fork(struct task_struct *t);
> [ 97s] | ^~~~~~~~~~~~~~~~~
>
> on !CONFIG_SCHED_MM_CID configs. (gcc15-15.2.1+git10776-2.3)
Indeed. I'll fix it before applying.
next prev parent reply other threads:[~2026-03-11 7:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-10 20:28 [patch 0/4] sched/mmcid: Cure fork()/vfork() related problems Thomas Gleixner
2026-03-10 20:28 ` [patch 1/4] sched/mmcid: Prevent CID stalls due to concurrent forks Thomas Gleixner
2026-03-11 7:33 ` Jiri Slaby
2026-03-11 7:49 ` Peter Zijlstra [this message]
2026-03-11 11:04 ` [tip: sched/urgent] " tip-bot2 for Thomas Gleixner
2026-03-10 20:28 ` [patch 2/4] sched/mmcid: Handle vfork()/CLONE_VM correctly Thomas Gleixner
2026-03-11 11:04 ` [tip: sched/urgent] " tip-bot2 for Thomas Gleixner
2026-03-10 20:29 ` [patch 3/4] sched/mmcid: Remove pointless preempt guard Thomas Gleixner
2026-03-11 11:04 ` [tip: sched/urgent] " tip-bot2 for Thomas Gleixner
2026-03-10 20:29 ` [patch 4/4] sched/mmcid: Avoid full tasklist walks Thomas Gleixner
2026-03-11 11:04 ` [tip: sched/urgent] " tip-bot2 for Thomas Gleixner
2026-03-11 9:43 ` [patch 0/4] sched/mmcid: Cure fork()/vfork() related problems Matthieu Baerts
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