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 10:30:16 +0200 [thread overview]
Message-ID: <20140707083016.GA19379@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <53B98709.3090603@oracle.com>
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On Sun, Jul 06, 2014 at 01:27:37PM -0400, Sasha Levin wrote:
> Hi all,
>
> While fuzzing with trinity inside a KVM tools guest running the latest -next
> kernel I've stumbled on the following spew:
>
> [10062.200152] BUG: spinlock recursion on CPU#11, trinity-c194/2414
> [10062.201897] lock: 0xffff88010cfd7740, .magic: dead4ead, .owner: trinity-c194/2414, .owner_cpu: -1
> [10062.204432] CPU: 11 PID: 2414 Comm: trinity-c194 Not tainted 3.16.0-rc3-next-20140703-sasha-00024-g2ad7668-dirty #763
> [10062.207517] ffff88010cfd7740 ffff8803a429fe48 ffffffffaa4897e4 0000000000000000
> [10062.209810] ffff8803c35f0000 ffff8803a429fe68 ffffffffaa47df58 ffff88010cfd7740
> [10062.210024] ffffffffab845c77 ffff8803a429fe88 ffffffffaa47df83 ffff88010cfd7740
> [10062.210024] Call Trace:
> [10062.210024] dump_stack (lib/dump_stack.c:52)
> [10062.210024] spin_dump (kernel/locking/spinlock_debug.c:68 (discriminator 6))
> [10062.210024] spin_bug (kernel/locking/spinlock_debug.c:76)
> [10062.210024] do_raw_spin_lock (kernel/locking/spinlock_debug.c:84 kernel/locking/spinlock_debug.c:135)
> [10062.210024] _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151)
> [10062.210024] ? task_rq_lock (include/linux/sched.h:2885 kernel/sched/core.c:348)
> [10062.210024] task_rq_lock (include/linux/sched.h:2885 kernel/sched/core.c:348)
> [10062.210024] SyS_sched_rr_get_interval (kernel/sched/core.c:4429 kernel/sched/core.c:4407)
> [10062.210024] ? tracesys (arch/x86/kernel/entry_64.S:531)
> [10062.210024] tracesys (arch/x86/kernel/entry_64.S:542)
Cute, but I'm utterly failing to see how that happened :/
All we should be holding there is the rcu_read_lock(), task_rq_lock()
there will take ->pi_lock and then rq->lock.
Maybe after more tea, when the brain wakes up more or so.. weird.
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next prev parent reply other threads:[~2014-07-07 8:30 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 [this message]
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
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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