4dc2375c1a
Rik reports that he sees an increase in CPU use in one benchmark due to commit 612f1a22f067 "cpuidle: poll_state: Add time limit to poll_idle()" that caused poll_idle() to call local_clock() in every iteration of the loop. Utilization increase generally means more non-idle time with respect to total CPU time (on the average) which implies reduced CPU frequency. Doug reports that limiting the rate of local_clock() invocations in there causes much less power to be drawn during a CPU-intensive parallel workload (with idle states 1 and 2 disabled to enforce more state 0 residency). These two reports together suggest that executing local_clock() on multiple CPUs in parallel at a high rate may cause chips to get hot and trigger thermal/power limits on them to kick in, so reduce the rate of local_clock() invocations in poll_idle() to avoid that issue. Fixes: 612f1a22f067 "cpuidle: poll_state: Add time limit to poll_idle()" Reported-by: Rik van Riel <riel@surriel.com> Reported-by: Doug Smythies <dsmythies@telus.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Rik van Riel <riel@surriel.com> Reviewed-by: Rik van Riel <riel@surriel.com> |
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| .. | ||
| governors | ||
| coupled.c | ||
| cpuidle-arm.c | ||
| cpuidle-at91.c | ||
| cpuidle-big_little.c | ||
| cpuidle-calxeda.c | ||
| cpuidle-clps711x.c | ||
| cpuidle-cps.c | ||
| cpuidle-exynos.c | ||
| cpuidle-kirkwood.c | ||
| cpuidle-mvebu-v7.c | ||
| cpuidle-powernv.c | ||
| cpuidle-pseries.c | ||
| cpuidle-ux500.c | ||
| cpuidle-zynq.c | ||
| cpuidle.c | ||
| cpuidle.h | ||
| driver.c | ||
| dt_idle_states.c | ||
| dt_idle_states.h | ||
| governor.c | ||
| Kconfig | ||
| Kconfig.arm | ||
| Kconfig.mips | ||
| Kconfig.powerpc | ||
| Makefile | ||
| poll_state.c | ||
| sysfs.c | ||