From: Peter Zijlstra <peterz@infradead.org>
To: lkp@lists.01.org
Subject: Re: [trace events] WARNING: CPU: 0 PID: 91 at kernel/sched/core.c:7253 __might_sleep()
Date: Wed, 08 Oct 2014 12:41:20 +0200 [thread overview]
Message-ID: <20141008104120.GH10832@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20141008100613.GA17869@wfg-t540p.sh.intel.com>
[-- Attachment #1: Type: text/plain, Size: 2649 bytes --]
On Wed, Oct 08, 2014 at 06:06:13PM +0800, Fengguang Wu wrote:
> [ 8.867644] WARNING: CPU: 0 PID: 91 at kernel/sched/core.c:7253 __might_sleep+0x9a/0x378()
> [ 8.869031] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff8d79b511>] event_test_thread+0x48/0x93
> [ 8.870533] Modules linked in:
> [ 8.870979] CPU: 0 PID: 91 Comm: test-events Not tainted 3.17.0-rc7-00109-g2f85d18 #37
> [ 8.872061] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
> [ 8.873428] 0000000000000000 ffff880010ec3c80 ffffffff8c696943 ffff880010ec3cb8
> [ 8.874503] ffffffff8be7cae5 ffffffff8bead236 0000000000000001 ffff88001161fa01
> [ 8.888390] 0000000000000001 0000000000000000 ffff880010ec3d20 ffffffff8be7cb46
> [ 8.890628] Call Trace:
> [ 8.890978] [<ffffffff8c696943>] dump_stack+0x19/0x1b
> [ 8.891689] [<ffffffff8be7cae5>] warn_slowpath_common+0x8f/0xa8
> [ 8.892535] [<ffffffff8bead236>] ? __might_sleep+0x9a/0x378
> [ 8.893307] [<ffffffff8be7cb46>] warn_slowpath_fmt+0x48/0x50
> [ 8.894083] [<ffffffff8be0dd55>] ? sched_clock+0x9/0xd
> [ 8.894797] [<ffffffff8d79b511>] ? event_test_thread+0x48/0x93
> [ 8.895602] [<ffffffff8d79b511>] ? event_test_thread+0x48/0x93
> [ 8.896421] [<ffffffff8bead236>] __might_sleep+0x9a/0x378
> [ 8.897164] [<ffffffff8c6a0227>] down_read+0x26/0x98
> [ 8.897855] [<ffffffff8be8f503>] exit_signals+0x27/0x1c2
> [ 8.898598] [<ffffffff8be7fedd>] do_exit+0x193/0x10bd
> [ 8.899298] [<ffffffff8bfd1969>] ? kfree+0x4a0/0x4d7
> [ 8.900028] [<ffffffff8d79b4c9>] ? event_trace_self_tests+0x6d7/0x6d7
> [ 8.900946] [<ffffffff8d79b4c9>] ? event_trace_self_tests+0x6d7/0x6d7
> [ 8.914871] [<ffffffff8bea4b65>] kthread+0x156/0x156
> [ 8.915571] [<ffffffff8c69c0f8>] ? wait_for_common+0x3e/0x224
> [ 8.916381] [<ffffffff8bea4a0f>] ? insert_kthread_work+0xe7/0xe7
> [ 8.917203] [<ffffffff8c6a353a>] ret_from_fork+0x7a/0xb0
> [ 8.917937] [<ffffffff8bea4a0f>] ? insert_kthread_work+0xe7/0xe7
> [ 8.918800] ---[ end trace 14d02ef17adbc114 ]---
Steve, wth is that thing supposed to do?
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop())
schedule();
That looks broken alright. It'll revert to a yield() 'spin' loop if it
ever gets a wakeup for anything other than the kthread_stop().
Did you mean to write something like:
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
schedule();
set_current_state(TASK_INTERRUPTIBLE);
}
__set_current_state(TASK_RUNNING);
?
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Jet Chen <jet.chen@intel.com>, Su Tao <tao.su@intel.com>,
Yuanhan Liu <yuanhan.liu@intel.com>, LKP <lkp@01.org>,
linux-kernel@vger.kernel.org
Subject: Re: [trace events] WARNING: CPU: 0 PID: 91 at kernel/sched/core.c:7253 __might_sleep()
Date: Wed, 8 Oct 2014 12:41:20 +0200 [thread overview]
Message-ID: <20141008104120.GH10832@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20141008100613.GA17869@wfg-t540p.sh.intel.com>
On Wed, Oct 08, 2014 at 06:06:13PM +0800, Fengguang Wu wrote:
> [ 8.867644] WARNING: CPU: 0 PID: 91 at kernel/sched/core.c:7253 __might_sleep+0x9a/0x378()
> [ 8.869031] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff8d79b511>] event_test_thread+0x48/0x93
> [ 8.870533] Modules linked in:
> [ 8.870979] CPU: 0 PID: 91 Comm: test-events Not tainted 3.17.0-rc7-00109-g2f85d18 #37
> [ 8.872061] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
> [ 8.873428] 0000000000000000 ffff880010ec3c80 ffffffff8c696943 ffff880010ec3cb8
> [ 8.874503] ffffffff8be7cae5 ffffffff8bead236 0000000000000001 ffff88001161fa01
> [ 8.888390] 0000000000000001 0000000000000000 ffff880010ec3d20 ffffffff8be7cb46
> [ 8.890628] Call Trace:
> [ 8.890978] [<ffffffff8c696943>] dump_stack+0x19/0x1b
> [ 8.891689] [<ffffffff8be7cae5>] warn_slowpath_common+0x8f/0xa8
> [ 8.892535] [<ffffffff8bead236>] ? __might_sleep+0x9a/0x378
> [ 8.893307] [<ffffffff8be7cb46>] warn_slowpath_fmt+0x48/0x50
> [ 8.894083] [<ffffffff8be0dd55>] ? sched_clock+0x9/0xd
> [ 8.894797] [<ffffffff8d79b511>] ? event_test_thread+0x48/0x93
> [ 8.895602] [<ffffffff8d79b511>] ? event_test_thread+0x48/0x93
> [ 8.896421] [<ffffffff8bead236>] __might_sleep+0x9a/0x378
> [ 8.897164] [<ffffffff8c6a0227>] down_read+0x26/0x98
> [ 8.897855] [<ffffffff8be8f503>] exit_signals+0x27/0x1c2
> [ 8.898598] [<ffffffff8be7fedd>] do_exit+0x193/0x10bd
> [ 8.899298] [<ffffffff8bfd1969>] ? kfree+0x4a0/0x4d7
> [ 8.900028] [<ffffffff8d79b4c9>] ? event_trace_self_tests+0x6d7/0x6d7
> [ 8.900946] [<ffffffff8d79b4c9>] ? event_trace_self_tests+0x6d7/0x6d7
> [ 8.914871] [<ffffffff8bea4b65>] kthread+0x156/0x156
> [ 8.915571] [<ffffffff8c69c0f8>] ? wait_for_common+0x3e/0x224
> [ 8.916381] [<ffffffff8bea4a0f>] ? insert_kthread_work+0xe7/0xe7
> [ 8.917203] [<ffffffff8c6a353a>] ret_from_fork+0x7a/0xb0
> [ 8.917937] [<ffffffff8bea4a0f>] ? insert_kthread_work+0xe7/0xe7
> [ 8.918800] ---[ end trace 14d02ef17adbc114 ]---
Steve, wth is that thing supposed to do?
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop())
schedule();
That looks broken alright. It'll revert to a yield() 'spin' loop if it
ever gets a wakeup for anything other than the kthread_stop().
Did you mean to write something like:
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
schedule();
set_current_state(TASK_INTERRUPTIBLE);
}
__set_current_state(TASK_RUNNING);
?
next prev parent reply other threads:[~2014-10-08 10:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-08 10:07 [trace events] WARNING: CPU: 0 PID: 91 at kernel/sched/core.c:7253 __might_sleep() Fengguang Wu
2014-10-08 10:41 ` Peter Zijlstra [this message]
2014-10-08 10:41 ` Peter Zijlstra
2014-10-08 15:08 ` Steven Rostedt
2014-10-08 15:08 ` Steven Rostedt
2014-10-08 15:48 ` Peter Zijlstra
2014-10-08 15:48 ` Peter Zijlstra
2014-10-08 16:17 ` Steven Rostedt
2014-10-08 16:17 ` Steven Rostedt
2014-10-08 16:36 ` Peter Zijlstra
2014-10-08 16:36 ` Peter Zijlstra
2014-10-08 16:51 ` [PATCH] trace: Robustify wait loop Peter Zijlstra
2014-10-08 16:51 ` Peter Zijlstra
2014-10-08 17:52 ` Steven Rostedt
2014-10-08 17:52 ` Steven Rostedt
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