Messages in this thread | | | Subject | Re: [PATCH] cpuidle: Add "cpuidle.use_deepest" to bypass governor and allow HW to go deep | From | Thomas Ilsche <> | Date | Thu, 16 Nov 2017 17:11:28 +0100 |
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On 2017-11-09 08:38, Len Brown wrote: > From: Len Brown <len.brown@intel.com> > > While there are several mechanisms (cmdline, sysfs, PM_QOS) to limit > cpuidle to shallow idle states, there is no simple mechanism > to give the hardware permission to enter the deeptest state permitted by PM_QOS. > > Here we create the "cpuidle.use_deepest" modparam to provide this capability. > > "cpuidle.use_deepest=Y" can be set at boot-time, and > /sys/module/cpuidle/use_deepest can be modified (with Y/N) at run-time.
This is a good option to have and can conveniently prevent idle power consumption issues. But that wouldn't be a reasonable default, would it? I still think there is an inherent need for a heuristic and a corresponding mitigation to avoid staying in a sleep state too long.
Best, Thomas
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