Re: sched: WARNING: at include/linux/cpumask.h:108 select_fallback_rq+0x241/0x280()

Sasha Levin
2012-03-30T15:00:39Z

On Fri, Mar 30, 2012 at 5:10 PM, Srivatsa S. Bhat
<srivatsa.bhat@linux.vnet.ibm.com> wrote:
> On 03/30/2012 02:02 AM, Sasha Levin wrote:
>
>> (and now with lkml)
>>
>> Hi all,
>>
>> I got the following spew using trinity in a kvm tools guest on the
>> latest linux-next kernel.
>>
>> This is the result of trying to offline CPU1. I'm not sure how to
>> reproduce it easily besides putting some pressure on the system and
>> shutting down CPUs until it happens.
>>
>> [  317.238839] Cannot set affinity for irq 0
>> [  317.238839] ------------[ cut here ]------------
>> [  317.238839] WARNING: at include/linux/cpumask.h:108
>> select_fallback_rq+0x241/0x280()
>> [  317.238839] Pid: 13, comm: migration/1 Not tainted
>> 3.3.0-next-20120329-sasha #4
>> [  317.238839] Call Trace:
>> [  317.238839]  [<ffffffff810b26b5>] warn_slowpath_common+0x75/0xb0
>> [  317.238839]  [<ffffffff810b2705>] warn_slowpath_null+0x15/0x20
>> [  317.238839]  [<ffffffff810e5991>] select_fallback_rq+0x241/0x280
>> [  317.238839]  [<ffffffff810f1a40>] ? dequeue_task_fair+0x100/0x100
>> [  317.238839]  [<ffffffff810f1a40>] ? dequeue_task_fair+0x100/0x100
>> [  317.238839]  [<ffffffff810ecd20>] migrate_tasks+0x80/0xf0
>> [  317.238839]  [<ffffffff826fe03a>] ? migration_call+0xae/0x16b
>> [  317.238839]  [<ffffffff826fe073>] migration_call+0xe7/0x16b
>> [  317.238839]  [<ffffffff810ddebf>] notifier_call_chain+0x5f/0x150
>> [  317.238839]  [<ffffffff810ddfb9>] __raw_notifier_call_chain+0x9/0x10
>> [  317.238839]  [<ffffffff810b489b>] __cpu_notify+0x1b/0x30
>> [  317.238839]  [<ffffffff826c3fbd>] take_cpu_down+0x2d/0x40
>> [  317.238839]  [<ffffffff811357fa>] stop_machine_cpu_stop+0xda/0x1a0
>> [  317.238839]  [<ffffffff81135720>] ? queue_stop_cpus_work+0x190/0x190
>> [  317.238839]  [<ffffffff811352ae>] cpu_stopper_thread+0xee/0x200
>> [  317.238839]  [<ffffffff82705c1a>] ? __schedule+0x49a/0x860
>> [  317.238839]  [<ffffffff811351c0>] ? res_counter_init+0x50/0x50
>> [  317.238839]  [<ffffffff810d715e>] kthread+0xbe/0xd0
>> [  317.238839]  [<ffffffff82709e74>] kernel_thread_helper+0x4/0x10
>> [  317.238839]  [<ffffffff810e3ee0>] ? finish_task_switch+0x80/0x110
>> [  317.238839]  [<ffffffff82708174>] ? retint_restore_args+0x13/0x13
>> [  317.238839]  [<ffffffff810d70a0>] ? __init_kthread_worker+0x70/0x70
>> [  317.238839]  [<ffffffff82709e70>] ? gs_change+0x13/0x13
>> [  317.238839] ---[ end trace 79079cf527253aab ]---
>> [  317.250645] [sched_delayed] process 2267 (trinity) no longer affine to cpu1
>> [  317.323711] CPU 1 is now offline
>> [  317.591059] [sched_delayed] process 1956 (trinity) no longer affine to cpu1
>> [  317.812110] [sched_delayed] process 2004 (trinity) no longer affine to cpu1
>> [  318.401016] [sched_delayed] process 2228 (trinity) no longer affine to cpu1
>> [  318.581015] [sched_delayed] process 2099 (trinity) no longer affine to cpu1
>> --
>
>
>
> Does this patch help?
>
> ---
>
> From: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> Subject: sched: Fix incorrect usage of for_each_cpu_mask() in select_fallback_rq()
>
> The function for_each_cpu_mask() expects a *pointer* to struct cpumask
> as its second argument, whereas select_fallback_rq() passes the value
> itself. And moreover, for_each_cpu_mask() has been marked as obselete
> in include/linux/cpumask.h. So move to the more appropriate for_each_cpu()
> variant.
>
> Reported-by: Sasha Levin <levinsasha928@gmail.com>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> ---

Works for me.

Tested-by: Sasha Levin <levinsasha928@gmail.com>