Messages in this thread | | | Date | Mon, 06 Feb 2012 08:55:44 +0100 | From | Jens Axboe <> | Subject | Re: [patch]block: fix ioc locking warning |
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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
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