From: Sasha Levin <sasha.levin@oracle.com>
To: Li Bin <huawei.libin@huawei.com>, Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Dave Jones <davej@redhat.com>,
rui.xiang@huawei.com, wengmeiling.weng@huawei.com
Subject: Re: sched: spinlock recursion in sched_rr_get_interval
Date: Fri, 26 Dec 2014 02:01:33 -0500 [thread overview]
Message-ID: <549D07CD.8000204@oracle.com> (raw)
In-Reply-To: <549D03F6.9090607@huawei.com>
On 12/26/2014 01:45 AM, Li Bin wrote:
> On 2014/7/8 4:05, Peter Zijlstra wrote:
>> > On Mon, Jul 07, 2014 at 09:55:43AM -0400, Sasha Levin wrote:
>>> >> I've also had this one, which looks similar:
>>> >>
>>> >> [10375.005884] BUG: spinlock recursion on CPU#0, modprobe/10965
>>> >> [10375.006573] lock: 0xffff8803a0fd7740, .magic: dead4ead, .owner: modprobe/10965, .owner_cpu: 15
>>> >> [10375.007412] CPU: 0 PID: 10965 Comm: modprobe Tainted: G W 3.16.0-rc3-next-20140704-sasha-00023-g26c0906-dirty #765
>> >
>> > Something's fucked; so we have:
>> >
>> > debug_spin_lock_before()
>> > SPIN_BUG_ON(lock->owner == current, "recursion");
>> >
> Hello，
> Does ACCESS_ONCE() can help this issue? I have no evidence that its lack is
> responsible for the issue, but I think here need it indeed. Is that right?
>
> SPIN_BUG_ON(ACCESS_ONCE(lock->owner) == current, "recursion");
Could you explain a bit more why do you think it's needed?
Thanks,
Sasha
next prev parent reply other threads:[~2014-12-26 7:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-06 17:27 sched: spinlock recursion in sched_rr_get_interval Sasha Levin
2014-07-07 8:30 ` Peter Zijlstra
2014-07-07 13:55 ` Sasha Levin
2014-07-07 20:05 ` Peter Zijlstra
2014-07-07 22:47 ` Sasha Levin
2014-07-28 23:08 ` Sasha Levin
2014-09-17 9:13 ` Jovi Zhangwei
2014-12-26 6:45 ` Li Bin
2014-12-26 7:01 ` Sasha Levin [this message]
2014-12-27 9:02 ` Li Bin
2014-12-27 9:52 ` Davidlohr Bueso
2014-12-27 15:52 ` Sasha Levin
2014-12-28 20:17 ` Davidlohr Bueso
2014-12-29 14:22 ` Sasha Levin
2014-12-30 1:04 ` Sasha Levin
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