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

Sasha Levin
2012-03-29T20:32:44Z

(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