From: Mike Galbraith <efault@gmx.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Alex Shi <alex.shi@linaro.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: 9908859acaa9 cpuidle/menu: add per CPU PM QoS resume latency consideration
Date: Wed, 22 Feb 2017 14:19:02 +0100 [thread overview]
Message-ID: <1487769542.4487.2.camel@gmx.de> (raw)
In-Reply-To: <20170222131218.GS6515@twins.programming.kicks-ass.net>
On Wed, 2017-02-22 at 14:12 +0100, Peter Zijlstra wrote:
> On Wed, Feb 22, 2017 at 01:56:37PM +0100, Mike Galbraith wrote:
> > Hi,
> >
> > Do we really need a spinlock for that in the idle loop?
>
> Urgh, that's broken on RT, you cannot schedule the idle loop.
That's what made me notice the obnoxious little bugger.
[ 77.608340] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:995
[ 77.608342] in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1
[ 77.608343] INFO: lockdep is turned off.
[ 77.608344] irq event stamp: 59222
[ 77.608353] hardirqs last enabled at (59221): [<ffffffff81105a1f>] rcu_idle_exit+0x2f/0x50
[ 77.608362] hardirqs last disabled at (59222): [<ffffffff810d4f1a>] do_idle+0x9a/0x290
[ 77.608372] softirqs last enabled at (0): [<ffffffff8107b8f1>] copy_process.part.34+0x5f1/0x22a0
[ 77.608374] softirqs last disabled at (0): [< (null)>] (null)
[ 77.608374] Preemption disabled at:
[ 77.608383] [<ffffffff817282b2>] schedule_preempt_disabled+0x22/0x30
[ 77.608387] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W E 4.11.0-rt9-rt #163
[ 77.608389] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0056.R01.1409242327 09/24/2014
[ 77.608390] Call Trace:
[ 77.608399] dump_stack+0x85/0xc8
[ 77.608405] ___might_sleep+0x15d/0x260
[ 77.608409] rt_spin_lock+0x24/0x80
[ 77.608419] dev_pm_qos_read_value+0x1e/0x40
[ 77.608424] menu_select+0x56/0x3e0
[ 77.608426] ? rcu_eqs_enter_common.isra.40+0x9d/0x160
[ 77.608435] cpuidle_select+0x13/0x20
[ 77.608438] do_idle+0x182/0x290
[ 77.608445] cpu_startup_entry+0x48/0x50
[ 77.608450] start_secondary+0x133/0x160
[ 77.608453] start_cpu+0x14/0x14
next prev parent reply other threads:[~2017-02-22 13:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-22 12:56 9908859acaa9 cpuidle/menu: add per CPU PM QoS resume latency consideration Mike Galbraith
2017-02-22 13:12 ` Peter Zijlstra
2017-02-22 13:19 ` Mike Galbraith [this message]
2017-02-22 14:31 ` Alex Shi
2017-02-22 14:39 ` Peter Zijlstra
2017-02-22 14:55 ` Alex Shi
2017-02-23 12:15 ` Rafael J. Wysocki
2017-02-23 13:08 ` Mike Galbraith
2017-02-23 13:58 ` Alex Shi
2017-02-23 13:55 ` Alex Shi
2017-02-23 22:34 ` Rafael J. Wysocki
2017-02-24 1:49 ` Alex Shi
2017-02-24 12:25 ` [PATCH] cpuidle: menu: Avoid taking spinlock for accessing QoS values Rafael J. Wysocki
2017-02-22 14:46 ` 9908859acaa9 cpuidle/menu: add per CPU PM QoS resume latency consideration Mike Galbraith
2017-02-22 14:53 ` Alex Shi
2017-02-22 15:03 ` Mike Galbraith
2017-02-22 15:36 ` Alex Shi
2017-02-22 15:46 ` Mike Galbraith
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