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Message-ID: <1459446905.4569.76.camel@linux.intel.com>
Date: Thu, 31 Mar 2016 10:55:05 -0700
From: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
To: Jörg Otte <jrg.otte@...il.com>,
"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: "Rafael J. Wysocki" <rafael@...nel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Linux PM list <linux-pm@...r.kernel.org>,
Doug Smythies <dsmythies@...us.net>
Subject: Re: [intel-pstate driver regression] processor frequency very high
even if in idle
On Thu, 2016-03-31 at 19:27 +0200, Jörg Otte wrote:
> 2016-03-31 17:43 GMT+02:00 Rafael J. Wysocki <rjw@...ysocki.net>:
> > On Thursday, March 31, 2016 05:25:18 PM Jörg Otte wrote:
> > > 2016-03-31 13:42 GMT+02:00 Rafael J. Wysocki <rjw@...ysocki.net>:
> > > > On Thursday, March 31, 2016 11:05:56 AM Jörg Otte wrote:
> > > >
> > > > [cut]
> > > >
> > > > > >
> > > > >
> > > > > Yes, works for me.
> > > > >
> > > > > CPUID(7): No-SGX
> > > > > CPU Avg_MHz Busy% Bzy_MHz TSC_MHz
> > > > > - 11 0.66 1682 2494
> > > > > 0 11 0.60 1856 2494
> > > > > 1 6 0.34 1898 2494
> > > > > 2 13 0.82 1628 2494
> > > > > 3 13 0.87 1528 2494
> > > > > CPU Avg_MHz Busy% Bzy_MHz TSC_MHz
> > > > > - 6 0.58 963 2494
> > > > > 0 8 0.83 957 2494
> > > > > 1 1 0.08 984 2494
> > > > > 2 10 1.04 975 2494
> > > > > 3 3 0.35 934 2494
> > > > >
> > > >
> >
> > [cut]
> >
> > > >
> > >
> > > No, this patch doesn't help.
> >
> > Well, more work to do then.
> >
> > I've just noticed a bug in this patch, which is not relevant for
> > the results,
> > but below is a new version.
> >
> > > CPUID(7): No-SGX
> > > CPU Avg_MHz Busy% Bzy_MHz TSC_MHz
> > > - 8 0.32 2507 2495
> > > 0 13 0.53 2505 2495
> > > 1 3 0.11 2523 2495
> > > 2 1 0.06 2555 2495
> > > 3 15 0.59 2500 2495
> > > CPU Avg_MHz Busy% Bzy_MHz TSC_MHz
> > > - 8 0.33 2486 2495
> > > 0 12 0.50 2482 2495
> > > 1 5 0.22 2489 2495
> > > 2 1 0.04 2492 2495
> > > 3 15 0.59 2487 2495
> >
> > Please apply the patch below and take a (1s or so) trace from the
> > pstate_sample
> > tracepoint (under /sys/kernel/debug/tracing/events/power/ on my
> > systems).
> >
> > Then please apply the revert instead of it and take a trace from
> > that tracepoint
> > again and send both of the traces to me.
> >
> > ---
> > From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > Subject: [PATCH] intel_pstate: Do not set utilization update hook
> > too early
> >
> > The utilization update hook in the intel_pstate driver is set too
> > early, as it only should be set after the policy has been fully
> > initialized by the core. That may cause intel_pstate_update_util()
> > to use incorrect data and put the CPUs into incorrect P-states as
> > a result.
> >
> > To prevent that from happening, make intel_pstate_set_policy() set
> > the utilization update hook instead of intel_pstate_init_cpu() so
> > intel_pstate_update_util() only runs when all things have been
> > initialized as appropriate.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > ---
> > drivers/cpufreq/intel_pstate.c | 27 +++++++++++++++++++--------
> > 1 file changed, 19 insertions(+), 8 deletions(-)
> >
> > Index: linux-pm/drivers/cpufreq/intel_pstate.c
> > ===================================================================
> > --- linux-pm.orig/drivers/cpufreq/intel_pstate.c
> > +++ linux-pm/drivers/cpufreq/intel_pstate.c
> > @@ -1103,7 +1103,6 @@ static int intel_pstate_init_cpu(unsigne
> > intel_pstate_sample(cpu, 0);
> >
> > cpu->update_util.func = intel_pstate_update_util;
> > - cpufreq_set_update_util_data(cpunum, &cpu->update_util);
> >
> > pr_debug("intel_pstate: controlling: cpu %d\n", cpunum);
> >
> > @@ -1122,18 +1121,29 @@ static unsigned int intel_pstate_get(uns
> > return get_avg_frequency(cpu);
> > }
> >
> > +static void intel_pstate_set_update_util_hook(unsigned int cpu)
> > +{
> > + cpufreq_set_update_util_data(cpu, &all_cpu_data[cpu]-
> > >update_util);
> > +}
> > +
> > +static void intel_pstate_clear_update_util_hook(unsigned int cpu)
> > +{
> > + cpufreq_set_update_util_data(cpu, NULL);
> > + synchronize_sched();
> > +}
> > +
> > static int intel_pstate_set_policy(struct cpufreq_policy *policy)
> > {
> > if (!policy->cpuinfo.max_freq)
> > return -ENODEV;
> >
> > + intel_pstate_clear_update_util_hook(policy->cpu);
> > +
> > if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
> > policy->max >= policy->cpuinfo.max_freq) {
> > pr_debug("intel_pstate: set performance\n");
> > limits = &performance_limits;
> > - if (hwp_active)
> > - intel_pstate_hwp_set(policy->cpus);
> > - return 0;
> > + goto out;
> > }
> >
> > pr_debug("intel_pstate: set powersave\n");
> > @@ -1163,6 +1173,9 @@ static int intel_pstate_set_policy(struc
> > limits->max_perf = div_fp(int_tofp(limits->max_perf_pct),
> > int_tofp(100));
> >
> > + out:
> > + intel_pstate_set_update_util_hook(policy->cpu);
> > +
> > if (hwp_active)
> > intel_pstate_hwp_set(policy->cpus);
> >
> > @@ -1187,8 +1200,7 @@ static void intel_pstate_stop_cpu(struct
> >
> > pr_debug("intel_pstate: CPU %d exiting\n", cpu_num);
> >
> > - cpufreq_set_update_util_data(cpu_num, NULL);
> > - synchronize_sched();
> > + intel_pstate_clear_update_util_hook(cpu_num);
> >
> > if (hwp_active)
> > return;
> > @@ -1455,8 +1467,7 @@ out:
> > get_online_cpus();
> > for_each_online_cpu(cpu) {
> > if (all_cpu_data[cpu]) {
> > - cpufreq_set_update_util_data(cpu, NULL);
> > - synchronize_sched();
> > + intel_pstate_clear_update_util_hook(cpu);
> > kfree(all_cpu_data[cpu]);
> > }
> > }
> >
>
> OK, patch is applied.
> After some configurations and compilations I'm there.
> Under pstate_sample I see:
> enable filter format id trigger
>
> what to do now ? (never did tracing before)'
# cd /sys/kernel/debug/tracing/
# echo 1 > events/power/pstate_sample/enable
# echo 1 > events/power/cpu_frequency/enable
# cat trace
Send us the trace file.
Also your kernel config doesn't have many modules, Is it a custom
configuration you do for your system?
Thanks,
Srinivas
>
> Thanks, Jörg
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