From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Tejun Heo <tj@kernel.org>
Cc: jiangshanlai@gmail.com, linux-kernel@vger.kernel.org
Subject: Re: WARN_ON_ONCE() in process_one_work()?
Date: Tue, 13 Jun 2017 15:31:03 -0700 [thread overview]
Message-ID: <20170613223103.GX3721@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170613205837.GB7359@htj.duckdns.org>
On Tue, Jun 13, 2017 at 04:58:37PM -0400, Tejun Heo wrote:
> Hello, Paul.
>
> On Fri, May 05, 2017 at 10:11:59AM -0700, Paul E. McKenney wrote:
> > Just following up... I have hit this bug a couple of times over the
> > past few days. Anything I can do to help?
>
> My apologies for dropping the ball on this. I've gone over the hot
> plug code in workqueue several times but can't really find how this
> would happen. Can you please apply the following patch and see what
> it says when the problem happens?
I have fired it up, thank you!
Last time I saw one failure in 21 hours of test runs, so I have kicked
of 42 one-hour test runs. Will see what happens tomorrow morning,
Pacific Time.
Thanx, Paul
> Thanks.
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index c74bf39ef764..bd2ce3cbfb41 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -1691,13 +1691,20 @@ static struct worker *alloc_worker(int node)
> static void worker_attach_to_pool(struct worker *worker,
> struct worker_pool *pool)
> {
> + int ret;
> +
> mutex_lock(&pool->attach_mutex);
>
> /*
> * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any
> * online CPUs. It'll be re-applied when any of the CPUs come up.
> */
> - set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask);
> + ret = set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask);
> +
> + WARN(ret && !(pool->flags & POOL_DISASSOCIATED),
> + "set_cpus_allowed_ptr failed, ret=%d pool->cpu/flags=%d/0x%x cpumask=%*pbl online=%*pbl active=%*pbl\n",
> + ret, pool->cpu, pool->flags, cpumask_pr_args(pool->attrs->cpumask),
> + cpumask_pr_args(cpu_online_mask), cpumask_pr_args(cpu_active_mask));
>
> /*
> * The pool->attach_mutex ensures %POOL_DISASSOCIATED remains
> @@ -2037,8 +2044,11 @@ __acquires(&pool->lock)
> lockdep_copy_map(&lockdep_map, &work->lockdep_map);
> #endif
> /* ensure we're on the correct CPU */
> - WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) &&
> - raw_smp_processor_id() != pool->cpu);
> + if (WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) &&
> + raw_smp_processor_id() != pool->cpu))
> + printk_once("XXX workfn=%pf pool->cpu/flags=%d/0x%x curcpu=%d online=%*pbl active=%*pbl\n",
> + work->func, pool->cpu, pool->flags, raw_smp_processor_id(),
> + cpumask_pr_args(cpu_online_mask), cpumask_pr_args(cpu_active_mask));
>
> /*
> * A single work shouldn't be executed concurrently by
>
next prev parent reply other threads:[~2017-06-13 22:31 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-01 16:57 WARN_ON_ONCE() in process_one_work()? Paul E. McKenney
2017-05-01 18:38 ` Paul E. McKenney
2017-05-01 18:44 ` Tejun Heo
2017-05-01 18:58 ` Paul E. McKenney
2017-05-05 17:11 ` Paul E. McKenney
2017-06-13 20:58 ` Tejun Heo
2017-06-13 22:31 ` Paul E. McKenney [this message]
2017-06-14 15:15 ` Paul E. McKenney
2017-06-15 15:38 ` Paul E. McKenney
2017-06-16 17:36 ` Paul E. McKenney
2017-06-17 11:53 ` Tejun Heo
2017-06-17 17:31 ` Paul E. McKenney
2017-06-18 10:40 ` Tejun Heo
2017-06-20 16:45 ` Paul E. McKenney
2017-06-21 15:30 ` Paul E. McKenney
2017-06-23 16:41 ` Paul E. McKenney
2017-06-27 16:27 ` Paul E. McKenney
2017-05-01 18:42 ` Tejun Heo
2017-05-01 19:42 ` Steven Rostedt
2017-05-01 19:50 ` Tejun Heo
2017-05-01 20:02 ` Steven Rostedt
2018-06-20 19:29 Paul E. McKenney
2018-07-02 21:05 ` Tejun Heo
2018-07-03 4:05 ` Paul E. McKenney
2018-07-03 16:40 ` Paul E. McKenney
2018-07-03 20:12 ` Tejun Heo
2018-07-03 21:44 ` Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170613223103.GX3721@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=jiangshanlai@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).