Messages in this thread | | | Date | Wed, 26 Jul 2017 14:00:10 -0700 | From | Saravana Kannan <> | Subject | Re: [Eas-dev] [PATCH V3 1/3] sched: cpufreq: Allow remote cpufreq callbacks |
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On 07/21/2017 06:03 AM, Peter Zijlstra wrote: > On Thu, Jul 13, 2017 at 12:14:37PM +0530, Viresh Kumar wrote: >> diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c >> index 47e24b5384b3..606b1a37a1af 100644 >> --- a/drivers/cpufreq/cpufreq_governor.c >> +++ b/drivers/cpufreq/cpufreq_governor.c >> @@ -275,6 +275,10 @@ static void dbs_update_util_handler(struct update_util_data *data, u64 time, >> struct policy_dbs_info *policy_dbs = cdbs->policy_dbs; >> u64 delta_ns, lst; >> >> + /* Don't allow remote callbacks */ >> + if (smp_processor_id() != data->cpu) >> + return; >> + > > The alternative is using some of that policy_dbs->policy->*cpus crud I > suppose, because:
No, the alternative is to pass it on to the CPU freq driver and let it decide what it wants to do. That's the whole point if having a CPU freq driver -- so that the generic code doesn't need to care about HW specific details. Which is the point I was making in an earlier email to Viresh's patch -- we shouldn't be doing any CPU check for the call backs at the scheduler or ever governor level.
That would simplify this whole thing by deleting a bunch of code. And having much simpler checks in those drivers that actually have to deal with their HW specific details.
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