From: Michael Ellerman <mpe@ellerman.id.au>
To: Eryu Guan <eguan@redhat.com>
Cc: tj@kernel.org, Balbir Singh <bsingharora@gmail.com>,
liwan@redhat.com,
"open list\:LINUX FOR POWERPC \(32-BIT AND 64-BIT\)"
<linuxppc-dev@lists.ozlabs.org>
Subject: Re: kworker with empty task->cpus_allowed (was Re: [v4.12-rc1 regression] mount ext4 fs results in kernel crash on PPC64le host)
Date: Tue, 04 Jul 2017 21:06:55 +1000 [thread overview]
Message-ID: <87r2xwxxyo.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170704082101.GM23360@eguan.usersys.redhat.com>
Eryu Guan <eguan@redhat.com> writes:
> On Tue, Jul 04, 2017 at 04:26:11PM +1000, Michael Ellerman wrote:
>> Eryu Guan <eguan@redhat.com> writes:
>> > On Fri, Jun 30, 2017 at 08:07:02PM +1000, Michael Ellerman wrote:
>> >>
>> >> Can you try this patch and see if it changes anything? (with the debug
>> >> still applied).
>> >
>> > This patch fixes the crash for me. After appliying this patch (with all
>> > other debug patches still applied), kernel didn't print any warnings or
>> > calltraces or debug messages.
>>
>> OK. It's not meant to fix it :)
>
> Understand.
>
>>
>> I can't form any connection between your bisection result and that
>> patch, nothing is making any sense TBH.
>>
>> What hardware are you on? And are you doing CPU hotplug or anything like that?
>
> It's a "PowerVM" guest (I'm not familiar with powerpc, I don't know what
> does that mean..) running on Power8 host. I didn't do any CPU hotplug or
> anything like that.
OK thanks.
We might have to try and sync up on irc so we can debug this a bit faster.
Can you try this hunk also?
cheers
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c74bf39ef764..7c55721b1f1d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3902,6 +3906,7 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq)
"ordering guarantee broken for workqueue %s\n", wq->name);
return ret;
} else {
+ WARN_ON(cpumask_empty(unbound_std_wq_attrs[highpri]->cpumask));
return apply_workqueue_attrs(wq, unbound_std_wq_attrs[highpri]);
}
}
next prev parent reply other threads:[~2017-07-04 11:06 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-28 8:32 [v4.12-rc1 regression] mount ext4 fs results in kernel crash on PPC64le host Eryu Guan
2017-06-28 17:16 ` Balbir Singh
2017-06-29 3:41 ` Eryu Guan
2017-06-29 8:47 ` Balbir Singh
2017-06-29 9:04 ` Eryu Guan
2017-06-29 10:05 ` Eryu Guan
2017-06-29 11:12 ` Michael Ellerman
2017-06-29 11:39 ` Eryu Guan
2017-06-29 12:06 ` kworker with empty task->cpus_allowed (was Re: [v4.12-rc1 regression] mount ext4 fs results in kernel crash on PPC64le host) Michael Ellerman
2017-06-29 13:59 ` Eryu Guan
2017-06-29 14:24 ` Tejun Heo
2017-06-30 1:08 ` Michael Ellerman
2017-06-30 11:56 ` Tejun Heo
2017-06-30 10:07 ` Michael Ellerman
2017-06-30 11:47 ` Eryu Guan
2017-07-04 6:26 ` Michael Ellerman
2017-07-04 8:21 ` Eryu Guan
2017-07-04 11:06 ` Michael Ellerman [this message]
2017-07-04 12:12 ` Eryu Guan
2017-06-29 4:54 ` [v4.12-rc1 regression] mount ext4 fs results in kernel crash on PPC64le host Michael Ellerman
2017-06-29 10:27 ` Michael Ellerman
2017-06-29 10:33 ` Eryu Guan
2017-06-29 12:13 ` Michael Ellerman
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