ipmi_thread() uses back-to-back schedule() to poll for command completion which, on some machines, can push up CPU consumption and heavily tax the scheduler locks leading to noticeable overall performance degradation.
This patch replaces schedule() with usleep_range(100, 200). This allows the sensor readings to finish resonably fast and the cpu consumption of the kthread is kept under several percents of a core. Signed-off-by: Tejun Heo <t...@kernel.org> --- drivers/char/ipmi/ipmi_si_intf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index f124a2d2bb9f..2143e3c10623 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -1010,7 +1010,7 @@ static int ipmi_thread(void *data) if (smi_result == SI_SM_CALL_WITHOUT_DELAY) ; /* do nothing */ else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait) - schedule(); + usleep_range(100, 200); else if (smi_result == SI_SM_IDLE) { if (atomic_read(&smi_info->need_watch)) { schedule_timeout_interruptible(100); _______________________________________________ Openipmi-developer mailing list Openipmi-developer@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openipmi-developer