On Tue, 01 Apr 2008 21:32:14 PDT, Andrew Morton said:
Been seeing these crop up once in a while - can take hours after a reboot
before I see the first one, but once I see one, I'm likely to see more, at
a frequency of anywhere from ~5seconds to ~10 minutes between BUG msgs.
BUG: scheduling while atomic: swapper/0/0xffffffff
Pid: 0, comm: swapper Tainted: P 2.6.25-rc8-mm1 #4
Call Trace:
[<ffffffff8020b2f4>] ? default_idle+0x0/0x74
[<ffffffff8022be19>] __schedule_bug+0x5d/0x61
[<ffffffff80552aea>] schedule+0x11a/0x9e4
[<ffffffff805536ce>] ? preempt_schedule+0x3c/0xaa
[<ffffffff802480f1>] ? hrtimer_forward+0x82/0x96
[<ffffffff804600a4>] ? cpuidle_idle_call+0x0/0xd5
[<ffffffff8020b2f4>] ? default_idle+0x0/0x74
[<ffffffff8020b2e0>] cpu_idle+0xf6/0x10a
[<ffffffff80540cb2>] rest_init+0x86/0x8a
Eventually, I end up with a basically hung system, and need to alt-sysrq-B.
Yes, I know it's tainted, and it's possible the root cause is a self-inflicted
buggy module - but the traceback above seems odd. Did some of my code manage
to idle the CPU while is_atomic was set, or is the path from cpu_idle on down
doing something it shouldn't be?
(I admit being confused - if my code was the source of the is_atomic error,
shouldn't it have been caught on the *previous* call to schedule - the one
that ran through all the queues and decided we should invoke idle?
