* clocksource: !keventd_up() && schedule_work() == oops
@ 2009-09-09 8:00 Jiri Slaby
2009-09-14 9:28 ` Jiri Slaby
0 siblings, 1 reply; 2+ messages in thread
From: Jiri Slaby @ 2009-09-09 8:00 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: Linux kernel mailing list
Hi,
I started to see oopses on boot in qemu machine because keventd is
created in kernel_init/do_basic_setup, but schedule_work is done earlier
in kernel_init/smp_init[1] when the tsc is unstable during this early phase.
It looks like "clocksource: Resolve cpu hotplug dead lock with TSC
unstable" is the culprit.
Creating its own either singlethread or "multithread" workqueue won't
work either (we do not have singlethread_cpu and cpu_populated_map).
Checking !keventd_up() in the clocksource code looks to me like a hack.
Any ideas, please?
[1]
kernel_init/smp_init/cpu_up/native_cpu_up/check_tsc_sync_source/mark_tsc_unstable/clocksource_mark_unstable/__clocksource_unstable
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: clocksource: !keventd_up() && schedule_work() == oops
2009-09-09 8:00 clocksource: !keventd_up() && schedule_work() == oops Jiri Slaby
@ 2009-09-14 9:28 ` Jiri Slaby
0 siblings, 0 replies; 2+ messages in thread
From: Jiri Slaby @ 2009-09-14 9:28 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: Linux kernel mailing list, Andrew Morton
On 09/09/2009 10:00 AM, Jiri Slaby wrote:
> Hi,
>
> I started to see oopses on boot in qemu machine because keventd is
> created in kernel_init/do_basic_setup, but schedule_work is done earlier
> in kernel_init/smp_init[1] when the tsc is unstable during this early phase.
>
> It looks like "clocksource: Resolve cpu hotplug dead lock with TSC
> unstable" is the culprit.
>
> Creating its own either singlethread or "multithread" workqueue won't
> work either (we do not have singlethread_cpu and cpu_populated_map).
> Checking !keventd_up() in the clocksource code looks to me like a hack.
> Any ideas, please?
Still present in mmotm 2009-09-14-01-57.
> [1]
> kernel_init/smp_init/cpu_up/native_cpu_up/check_tsc_sync_source/mark_tsc_unstable/clocksource_mark_unstable/__clocksource_unstable
^ permalink raw reply [flat|nested] 2+ messages in thread
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