From: Oleg Nesterov <oleg@redhat.com>
To: Roman Pen <roman.penyaev@profitbricks.com>
Cc: Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Tejun Heo <tj@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/1] workqueue: ignore dead tasks in a workqueue sleep hook
Date: Wed, 26 Oct 2016 16:18:35 +0200 [thread overview]
Message-ID: <20161026141834.GB6893@redhat.com> (raw)
In-Reply-To: <20161025182742.10486-1-roman.penyaev@profitbricks.com>
On 10/25, Roman Pen wrote:
>
> void wq_worker_waking_up(struct task_struct *task, int cpu)
> {
> - struct worker *worker = kthread_data(task);
> + struct worker *worker;
> +
> + if (task->flags & PF_EXITING) {
> + /*
> + * Careful here, t->vfork_done is zeroed out for
> + * almost dead tasks, do not touch kthread_data().
> + */
> + return;
> + }
> +
> + worker = kthread_data(task);
>
> if (!(worker->flags & WORKER_NOT_RUNNING)) {
> WARN_ON_ONCE(worker->pool->cpu != cpu);
> @@ -875,9 +885,19 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
> */
> struct task_struct *wq_worker_sleeping(struct task_struct *task)
> {
> - struct worker *worker = kthread_data(task), *to_wakeup = NULL;
> + struct worker *worker, *to_wakeup = NULL;
> struct worker_pool *pool;
>
> + if (task->flags & PF_EXITING) {
> + /*
> + * Careful here, t->vfork_done is zeroed out for
> + * almost dead tasks, do not touch kthread_data().
> + */
> + return NULL;
> + }
> +
> + worker = kthread_data(task);
> +
Please see the patch I send a minute ago. With that patch we do not need
this fix, kthread_data() no longer uses ->vfork_done.
Oleg.
next prev parent reply other threads:[~2016-10-26 14:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-25 18:27 [PATCH v4 1/1] workqueue: ignore dead tasks in a workqueue sleep hook Roman Pen
2016-10-26 14:18 ` Oleg Nesterov [this message]
2016-10-26 15:43 ` Roman Penyaev
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