From: Jens Axboe <axboe@kernel.dk>
To: Shaohua Li <shaohua.li@intel.com>
Cc: lkml <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Tejun Heo <tj@kernel.org>,
Knut Petersen <Knut_Petersen@t-online.de>,
mroos@linux.ee
Subject: Re: [patch]block: fix ioc locking warning
Date: Mon, 06 Feb 2012 08:55:44 +0100 [thread overview]
Message-ID: <4F2F8780.5060207@kernel.dk> (raw)
In-Reply-To: <1328514611.21268.66.camel@sli10-conroe>
On 02/06/2012 08:50 AM, Shaohua Li wrote:
> Meelis reported a warning:
>
> WARNING: at kernel/timer.c:1122 run_timer_softirq+0x199/0x1ec()
> Hardware name: 939Dual-SATA2
> timer: cfq_idle_slice_timer+0x0/0xaa preempt leak: 00000102 -> 00000103
> Modules linked in: sr_mod cdrom videodev media drm_kms_helper ohci_hcd ehci_hcd v4l2_compat_ioctl32 usbcore i2c_ali15x3 snd_seq drm snd_timer snd_seq
> Pid: 0, comm: swapper Not tainted 3.3.0-rc2-00110-gd125666 #176
> Call Trace:
> <IRQ> [<ffffffff81022aaa>] warn_slowpath_common+0x7e/0x96
> [<ffffffff8114c485>] ? cfq_slice_expired+0x1d/0x1d
> [<ffffffff81022b56>] warn_slowpath_fmt+0x41/0x43
> [<ffffffff8114c526>] ? cfq_idle_slice_timer+0xa1/0xaa
> [<ffffffff8114c485>] ? cfq_slice_expired+0x1d/0x1d
> [<ffffffff8102c124>] run_timer_softirq+0x199/0x1ec
> [<ffffffff81047a53>] ? timekeeping_get_ns+0x12/0x31
> [<ffffffff810145fd>] ? apic_write+0x11/0x13
> [<ffffffff81027475>] __do_softirq+0x74/0xfa
> [<ffffffff812f337a>] call_softirq+0x1a/0x30
> [<ffffffff81002ff9>] do_softirq+0x31/0x68
> [<ffffffff810276cf>] irq_exit+0x3d/0xa3
> [<ffffffff81014aca>] smp_apic_timer_interrupt+0x6b/0x77
> [<ffffffff812f2de9>] apic_timer_interrupt+0x69/0x70
> <EOI> [<ffffffff81040136>] ? sched_clock_cpu+0x73/0x7d
> [<ffffffff81040136>] ? sched_clock_cpu+0x73/0x7d
> [<ffffffff8100801f>] ? default_idle+0x1e/0x32
> [<ffffffff81008019>] ? default_idle+0x18/0x32
> [<ffffffff810008b1>] cpu_idle+0x87/0xd1
> [<ffffffff812de861>] rest_init+0x85/0x89
> [<ffffffff81659a4d>] start_kernel+0x2eb/0x2f8
> [<ffffffff8165926e>] x86_64_start_reservations+0x7e/0x82
> [<ffffffff81659362>] x86_64_start_kernel+0xf0/0xf7
>
> this_q == locked_q is possible. There are two problems here:
> 1. In UP case, there is preemption counter issue as spin_trylock always
> successes.
> 2. In SMP case, the loop breaks too earlier.
Thanks Shaohua, applied!
--
Jens Axboe
next prev parent reply other threads:[~2012-02-06 7:56 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-06 7:50 [patch]block: fix ioc locking warning Shaohua Li
2012-02-06 7:55 ` Jens Axboe [this message]
2012-02-06 15:12 ` Vivek Goyal
2012-02-06 16:09 ` Jens Axboe
2012-02-06 16:37 ` Vivek Goyal
2012-02-06 16:44 ` Tejun Heo
2012-02-06 16:58 ` Linus Torvalds
2012-02-06 17:27 ` Tejun Heo
2012-02-06 20:16 ` Jens Axboe
2012-02-06 21:54 ` [PATCH] block: strip out locking optimization in put_io_context() Tejun Heo
2012-02-07 6:49 ` Jens Axboe
2012-02-07 16:22 ` Tejun Heo
2012-02-07 16:28 ` Jens Axboe
2012-02-07 16:33 ` Linus Torvalds
2012-02-07 16:47 ` Tejun Heo
2012-02-07 17:17 ` Tejun Heo
2012-02-08 0:19 ` Shaohua Li
2012-02-08 8:29 ` Shaohua Li
2012-02-08 16:29 ` Tejun Heo
2012-02-08 16:34 ` Linus Torvalds
2012-02-08 16:49 ` Tejun Heo
2012-02-08 16:56 ` Tejun Heo
2012-02-08 17:23 ` Tejun Heo
2012-02-09 6:22 ` Shaohua Li
2012-02-09 17:59 ` Tejun Heo
2012-02-09 18:07 ` Linus Torvalds
2012-02-09 19:24 ` Tejun Heo
2012-02-09 23:48 ` Tejun Heo
2012-02-10 5:14 ` Shaohua Li
2012-02-10 8:48 ` Shaohua Li
2012-02-11 2:17 ` Tejun Heo
2012-02-11 11:35 ` Jens Axboe
2012-02-13 1:34 ` Shaohua Li
2012-02-13 20:49 ` Tejun Heo
2012-02-14 2:36 ` Shaohua Li
2012-02-14 16:39 ` Tejun Heo
2012-02-10 3:09 ` Shaohua Li
2012-02-07 23:00 ` [PATCH] block: fix lockdep warning on io_context release put_io_context() Tejun Heo
2012-02-06 20:36 ` [patch]block: fix ioc locking warning Tejun Heo
2012-02-07 0:31 ` Shaohua Li
2012-02-07 0:39 ` Tejun Heo
2012-02-07 0:43 ` Shaohua Li
2012-02-07 0:59 ` Tejun Heo
2012-02-07 1:10 ` Shaohua Li
2012-02-07 1:33 ` Shaohua Li
2012-02-07 5:22 ` Shaohua Li
2012-02-07 22:34 ` Linus Torvalds
2012-02-06 16:22 ` Tejun Heo
2012-02-08 18:07 ` walt
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