Re: [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