lkml.org 
[lkml]   [2012]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: RCU lockup in the SMP idle thread, help...
    On Fri, Sep 14, 2012 at 09:27:32AM +0200, Linus Walleij wrote:
    > On Thu, Sep 13, 2012 at 6:58 PM, Paul E. McKenney
    > <paulmck@linux.vnet.ibm.com> wrote:
    > > On Thu, Sep 13, 2012 at 09:49:14AM -0700, John Stultz wrote:
    > >> I saw this once as well testing the fix to Daniel's deep idle hang
    > >> issue (also on 32 bit).
    >
    > John, what system was this? If it's not Snowball/ux500 we can atleast
    > conclude that
    > it's a generic bug, not machine-specific...
    >
    > >> Really briefly looking at the code in rcutree.c, I'm curious if
    > >> we're hitting a false positive on the 5 minute jiffies overflow?
    > >
    > > Hmmm... Might be. Does the patch below help?
    >
    > Sorry, nope, I get this:

    Could you please try reproducing with CONFIG_RCU_CPU_STALL_INFO=y?

    Thanx, Paul

    > root@ME:/
    > root@ME:/ INFO: rcu_preempt detected stalls on CPUs/tasks: { 0}
    > (detected by 1, t=29545 jiffies)
    > [<c0014710>] (unwind_backtrace+0x0/0xf8) from [<c00686fc>]
    > (rcu_check_callbacks+0x6e0/0x76c)
    > [<c00686fc>] (rcu_check_callbacks+0x6e0/0x76c) from [<c0029cbc>]
    > (update_process_times+0x38/0x4c)
    > [<c0029cbc>] (update_process_times+0x38/0x4c) from [<c0055088>]
    > (tick_sched_timer+0x80/0xe4)
    > [<c0055088>] (tick_sched_timer+0x80/0xe4) from [<c003c120>]
    > (__run_hrtimer.isra.18+0x44/0xd0)
    > [<c003c120>] (__run_hrtimer.isra.18+0x44/0xd0) from [<c003cae0>]
    > (hrtimer_interrupt+0x118/0x2b4)
    > [<c003cae0>] (hrtimer_interrupt+0x118/0x2b4) from [<c0013658>]
    > (twd_handler+0x30/0x44)
    > [<c0013658>] (twd_handler+0x30/0x44) from [<c00638c8>]
    > (handle_percpu_devid_irq+0x80/0xa0)
    > [<c00638c8>] (handle_percpu_devid_irq+0x80/0xa0) from [<c00603b8>]
    > (generic_handle_irq+0x20/0x30)
    > [<c00603b8>] (generic_handle_irq+0x20/0x30) from [<c000ef58>]
    > (handle_IRQ+0x4c/0xac)
    > [<c000ef58>] (handle_IRQ+0x4c/0xac) from [<c00084bc>] (gic_handle_irq+0x24/0x58)
    > [<c00084bc>] (gic_handle_irq+0x24/0x58) from [<c000dc80>] (__irq_svc+0x40/0x70)
    > Exception stack(0xcf865f88 to 0xcf865fd0)
    > 5f80: 00000020 c05c0a20 00000001 00000000 cf864000 cf864000
    > 5fa0: c05dfe48 c02de0bc c05c3e90 412fc091 cf864000 00000000 01000000 cf865fd0
    > 5fc0: c000f234 c000f238 60000013 ffffffff
    > [<c000dc80>] (__irq_svc+0x40/0x70) from [<c000f238>] (default_idle+0x28/0x30)
    > [<c000f238>] (default_idle+0x28/0x30) from [<c000f438>] (cpu_idle+0x98/0xe4)
    > [<c000f438>] (cpu_idle+0x98/0xe4) from [<002d3094>] (0x2d3094)
    > INFO: rcu_preempt detected stalls on CPUs/tasks: { 0} (detected by 1,
    > t=30029 jiffies)
    > [<c0014710>] (unwind_backtrace+0x0/0xf8) from [<c00686fc>]
    > (rcu_check_callbacks+0x6e0/0x76c)
    > [<c00686fc>] (rcu_check_callbacks+0x6e0/0x76c) from [<c0029cbc>]
    > (update_process_times+0x38/0x4c)
    > [<c0029cbc>] (update_process_times+0x38/0x4c) from [<c0055088>]
    > (tick_sched_timer+0x80/0xe4)
    > [<c0055088>] (tick_sched_timer+0x80/0xe4) from [<c003c120>]
    > (__run_hrtimer.isra.18+0x44/0xd0)
    > [<c003c120>] (__run_hrtimer.isra.18+0x44/0xd0) from [<c003cae0>]
    > (hrtimer_interrupt+0x118/0x2b4)
    > [<c003cae0>] (hrtimer_interrupt+0x118/0x2b4) from [<c0013658>]
    > (twd_handler+0x30/0x44)
    > [<c0013658>] (twd_handler+0x30/0x44) from [<c00638c8>]
    > (handle_percpu_devid_irq+0x80/0xa0)
    > [<c00638c8>] (handle_percpu_devid_irq+0x80/0xa0) from [<c00603b8>]
    > (generic_handle_irq+0x20/0x30)
    > [<c00603b8>] (generic_handle_irq+0x20/0x30) from [<c000ef58>]
    > (handle_IRQ+0x4c/0xac)
    > [<c000ef58>] (handle_IRQ+0x4c/0xac) from [<c00084bc>] (gic_handle_irq+0x24/0x58)
    > [<c00084bc>] (gic_handle_irq+0x24/0x58) from [<c000dc80>] (__irq_svc+0x40/0x70)
    > Exception stack(0xcf865f88 to 0xcf865fd0)
    > 5f80: 00000020 c05c0a20 00000001 00000000 cf864000 cf864000
    > 5fa0: c05dfe48 c02de0bc c05c3e90 412fc091 cf864000 00000000 01000000 cf865fd0
    > 5fc0: c000f234 c000f238 60000013 ffffffff
    > [<c000dc80>] (__irq_svc+0x40/0x70) from [<c000f238>] (default_idle+0x28/0x30)
    > [<c000f238>] (default_idle+0x28/0x30) from [<c000f438>] (cpu_idle+0x98/0xe4)
    > [<c000f438>] (cpu_idle+0x98/0xe4) from [<002d3094>] (0x2d3094)
    >
    > I'm all confused ..
    >
    > Yours,
    > Linus Walleij
    >



    \
     
     \ /
      Last update: 2012-09-14 20:41    [W:0.056 / U:30.644 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site