| Message ID | 20171103133642.8636-1-chris.redpath@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] cpufreq: schedutil: Examine the correct CPU when we update util | expand |
On 03-11-17, 13:36, Chris Redpath wrote: > After > 674e75411fc2 ("sched: cpufreq: Allow remote cpufreq callbacks") > > We stopped always reading utilization for the cpu we are running > the governor on, and instead read it for the cpu which we've been > told has updated utilization. This is stored in sugov_cpu->cpu. > > The value is set in sugov_register but we clear it in sugov_start > which leads to always looking at the utilization of CPU0 instead > of the correct one. > > Let's fix this by consolidating the initialization code into > sugov_start(). > > Fixes: 674e75411fc2 ("sched: cpufreq: Allow remote cpufreq callbacks") > Signed-off-by: Chris Redpath <chris.redpath@arm.com> > Reviewed-by: Patrick Bellasi <patrick.bellasi@arm.com> > Reviewed-by: Brendan Jackman <brendan.jackman@arm.com> > Cc: Rafael J. Wysocki <rjw@rjwysocki.net> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > --- > kernel/sched/cpufreq_schedutil.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) Acked-by: Viresh Kumar <viresh.kumar@linaro.org> -- viresh
Hi Viresh, Rafael, Without this patch, schedutil is totally broken for us - is there any chance at all this could go in 4.14 or is it just too late? Best Regards, Chris On 03/11/17 15:45, Viresh Kumar wrote: > On 03-11-17, 13:36, Chris Redpath wrote: >> After >> 674e75411fc2 ("sched: cpufreq: Allow remote cpufreq callbacks") >> >> We stopped always reading utilization for the cpu we are running >> the governor on, and instead read it for the cpu which we've been >> told has updated utilization. This is stored in sugov_cpu->cpu. >> >> The value is set in sugov_register but we clear it in sugov_start >> which leads to always looking at the utilization of CPU0 instead >> of the correct one. >> >> Let's fix this by consolidating the initialization code into >> sugov_start(). >> >> Fixes: 674e75411fc2 ("sched: cpufreq: Allow remote cpufreq callbacks") >> Signed-off-by: Chris Redpath <chris.redpath@arm.com> >> Reviewed-by: Patrick Bellasi <patrick.bellasi@arm.com> >> Reviewed-by: Brendan Jackman <brendan.jackman@arm.com> >> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> >> Cc: Viresh Kumar <viresh.kumar@linaro.org> >> Cc: Ingo Molnar <mingo@redhat.com> >> Cc: Peter Zijlstra <peterz@infradead.org> >> --- >> kernel/sched/cpufreq_schedutil.c | 6 +----- >> 1 file changed, 1 insertion(+), 5 deletions(-) > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
On 07-11-17, 09:49, Chris Redpath wrote: > Hi Viresh, Rafael, > > Without this patch, schedutil is totally broken for us - is > there any chance at all this could go in 4.14 or is it just > too late? I see that Rafael has already applied it, but not sure if he is planning to send it for 4.14 (though he should IMHO, as it is a critical fix). commit d62d813c0d71 ("cpufreq: schedutil: Examine the correct CPU when we update util") -- viresh
On Tue, Nov 7, 2017 at 10:59 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote: > On 07-11-17, 09:49, Chris Redpath wrote: >> Hi Viresh, Rafael, >> >> Without this patch, schedutil is totally broken for us - is >> there any chance at all this could go in 4.14 or is it just >> too late? > > I see that Rafael has already applied it, but not sure if he is planning to send > it for 4.14 (though he should IMHO, as it is a critical fix). Yes, I am. Thanks, Rafael
Thanks guys, really appreciated! --Chris On 07/11/17 10:09, Rafael J. Wysocki wrote: > On Tue, Nov 7, 2017 at 10:59 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote: >> On 07-11-17, 09:49, Chris Redpath wrote: >>> Hi Viresh, Rafael, >>> >>> Without this patch, schedutil is totally broken for us - is >>> there any chance at all this could go in 4.14 or is it just >>> too late? >> >> I see that Rafael has already applied it, but not sure if he is planning to send >> it for 4.14 (though he should IMHO, as it is a critical fix). > > Yes, I am. > > Thanks, > Rafael >
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 6c1a7fcfa2a7..dc68a1ccdb33 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -728,6 +728,7 @@ static int sugov_start(struct cpufreq_policy *policy) struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); memset(sg_cpu, 0, sizeof(*sg_cpu)); + sg_cpu->cpu = cpu; sg_cpu->sg_policy = sg_policy; sg_cpu->flags = SCHED_CPUFREQ_RT; sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq; @@ -793,11 +794,6 @@ struct cpufreq_governor *cpufreq_default_governor(void) static int __init sugov_register(void) { - int cpu; - - for_each_possible_cpu(cpu) - per_cpu(sugov_cpu, cpu).cpu = cpu; - return cpufreq_register_governor(&schedutil_gov); } fs_initcall(sugov_register);
After 674e75411fc2 ("sched: cpufreq: Allow remote cpufreq callbacks") We stopped always reading utilization for the cpu we are running the governor on, and instead read it for the cpu which we've been told has updated utilization. This is stored in sugov_cpu->cpu. The value is set in sugov_register but we clear it in sugov_start which leads to always looking at the utilization of CPU0 instead of the correct one. Let's fix this by consolidating the initialization code into sugov_start(). Fixes: 674e75411fc2 ("sched: cpufreq: Allow remote cpufreq callbacks") Signed-off-by: Chris Redpath <chris.redpath@arm.com> Reviewed-by: Patrick Bellasi <patrick.bellasi@arm.com> Reviewed-by: Brendan Jackman <brendan.jackman@arm.com> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> --- kernel/sched/cpufreq_schedutil.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) -- 2.13.1.449.g02a2850