On 07/14/2014 07:53 PM, Steven Rostedt wrote:
> On Mon, 14 Jul 2014 19:09:48 -0500
> Corey Minyard <cminyard@xxxxxxxxxx> wrote:
>
>> Can we get:
>>
>> tracing-use-migrate_disable-to-prevent-beeing-pushed.patch
> Sure except that patch is buggy:
>
> - preempt_disable();
> + migrate_disable();
> /* The update must run on the CPU that is being updated. */
> if (cpu_id == smp_processor_id() || !cpu_online(cpu_id))
> rb_update_pages(cpu_buffer);
> else {
> - /*
> - * Can not disable preemption for schedule_work_on()
> - * on PREEMPT_RT.
> - */
> - preempt_enable();
> schedule_work_on(cpu_id,
> &cpu_buffer->update_pages_work);
> wait_for_completion(&cpu_buffer->update_done);
> - preempt_disable();
> }
> - preempt_enable();
> + migrate_enable();
>
> migrate_disable() on non-PREEMPT_RT is preempt_disable(). You can't
> call wait_or_completion with preemption disabled.
>
> When that gets fixed in mainline -rt, I'll add it to the stable
> branches too.
I originally did a patch that just always did the else clause (the
schedule_work_on() and wait_for_completion()) on all CPUs. That seemed
to work just fine and simplifies the code a bit and gets rid of all the
preempt/migrate calls. You could try that approach, or I could submit
something if you liked.
-corey
>
> -- Steve
>
>
>
>> into 3.10, also?
>>
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
