Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH][v2] sched: cpufreq: Fix long idle judgement logic in load calculation | Date | Tue, 12 Jun 2018 17:05:46 +0200 |
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On Friday, June 8, 2018 6:04:13 AM CEST Viresh Kumar wrote: > On 08-06-18, 09:07, Chen Yu wrote: > > According to current code implementation, detecting the long > > idle period is done by checking if the interval between two > > adjacent utilization update handers is long enough. Although > > this mechanism can detect if the idle period is long enough > > (no utilization hooks invoked during idle period), it might > > not contain a corner case: if the task has occupied the cpu > > for too long which causes no context switch during that > > period, then no utilization handler will be launched until this > > high prio task is switched out. As a result, the idle_periods > > field might be calculated incorrectly because it regards the > > 100% load as 0% and makes the conservative governor who uses > > this field confusing. > > > > Change the judgement to compare the idle_time with sampling_rate > > directly. > > > > Reported-by: Artem S. Tashkinov <t.artem@mailcity.com> > > Cc: Artem S Tashkinov <t.artem@mailcity.com> > > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > > Cc: Viresh Kumar <viresh.kumar@linaro.org> > > Cc: linux-pm@vger.kernel.org > > Signed-off-by: Chen Yu <yu.c.chen@intel.com> > > --- > > v2: Per Viresh's suggestion, ignore idle_time longer than 30mins and > > simplify the code. > > --- > > drivers/cpufreq/cpufreq_governor.c | 12 +++++------- > > 1 file changed, 5 insertions(+), 7 deletions(-) > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Patch applied, thanks!
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