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SubjectRe: [PATCH 4.19 012/106] ipmi_si: Only schedule continuously in the thread in maintenance mode
Hi!

> @@ -1013,11 +1016,20 @@ static int ipmi_thread(void *data)
> spin_unlock_irqrestore(&(smi_info->si_lock), flags);
> busy_wait = ipmi_thread_busy_wait(smi_result, smi_info,
> &busy_until);
> - if (smi_result == SI_SM_CALL_WITHOUT_DELAY)
> + if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
> ; /* do nothing */
> - else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait)
> - schedule();
> - else if (smi_result == SI_SM_IDLE) {
> + } else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait) {
> + /*
> + * In maintenance mode we run as fast as
> + * possible to allow firmware updates to
> + * complete as fast as possible, but normally
> + * don't bang on the scheduler.
> + */
> + if (smi_info->in_maintenance_mode)
> + schedule();
> + else
> + usleep_range(100, 200);
> + } else if (smi_result == SI_SM_IDLE) {

This is quite crazy code. usleep() will need to do magic with high
resolution timers to provide 200usec sleep... when all you want to do
is unload the scheduler.

cond_resched() should be okay to call in a loop, can the code use that
instead?

Best regards,
Pavel

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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