From: Peter Zijlstra <peterz@infradead.org>
To: Sasha Levin <sasha.levin@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Dave Jones <davej@redhat.com>
Subject: Re: sched: spinlock recursion in sched_rr_get_interval
Date: Mon, 7 Jul 2014 22:05:50 +0200 [thread overview]
Message-ID: <20140707200550.GA6758@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <53BAA6DF.5060409@oracle.com>
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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");
Causing that, _HOWEVER_ look at .owner_cpu and the reporting cpu!! How
can the lock owner, own the lock on cpu 15 and again contend with it on
CPU 0. That's impossible.
About when-ish did you start seeing things like this? Lemme go stare
hard at recent changes.
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next prev parent reply other threads:[~2014-07-07 20:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-06 17:27 Sasha Levin
2014-07-07 8:30 ` Peter Zijlstra
2014-07-07 13:55 ` Sasha Levin
2014-07-07 20:05 ` Peter Zijlstra [this message]
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
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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