| Message ID | 1724762.8Kf4o5e5cm@vostro.rjw.lan (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Rafael Wysocki |
| Headers | show |
On Wed, 2016-10-19 at 02:57 +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > After commit a4675fbc4a7a (cpufreq: intel_pstate: Replace timers with > utilization update callbacks) the cpufreq governor callbacks may not > be invoked on NOHZ_FULL CPUs and, in particular, switching to the > "performance" policy via sysfs may not have any effect on them. That > is a problem, because it usually is desirable to squeeze the last > bit of performance out of those CPUs, so work around it by setting > the maximum P-state (within the limits) in intel_pstate_set_policy() > upfront when the policy is CPUFREQ_POLICY_PERFORMANCE. > > Fixes: a4675fbc4a7a (cpufreq: intel_pstate: Replace timers with > utilization update callbacks) > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > --- > drivers/cpufreq/intel_pstate.c | 29 +++++++++++++++++++++++++---- > 1 file changed, 25 insertions(+), 4 deletions(-) > > Index: linux-pm/drivers/cpufreq/intel_pstate.c > =================================================================== > --- linux-pm.orig/drivers/cpufreq/intel_pstate.c > +++ linux-pm/drivers/cpufreq/intel_pstate.c > @@ -1137,10 +1137,8 @@ static void intel_pstate_get_min_max(str > *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, > max_perf); > } > > -static void intel_pstate_set_min_pstate(struct cpudata *cpu) > +static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate) > { > - int pstate = cpu->pstate.min_pstate; > - > trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu); > cpu->pstate.current_pstate = pstate; > /* > @@ -1152,6 +1150,20 @@ static void intel_pstate_set_min_pstate( > pstate_funcs.get_val(cpu, pstate)); > } > > +static void intel_pstate_set_min_pstate(struct cpudata *cpu) > +{ > + intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate); > +} > + > +static void intel_pstate_max_within_limits(struct cpudata *cpu) > +{ > + int min_pstate, max_pstate; > + > + update_turbo_state(); > + intel_pstate_get_min_max(cpu, &min_pstate, &max_pstate); > + intel_pstate_set_pstate(cpu, max_pstate); > +} > + > static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) > { > cpu->pstate.min_pstate = pstate_funcs.get_min(); > @@ -1485,7 +1497,7 @@ static int intel_pstate_set_policy(struc > pr_debug("set_policy cpuinfo.max %u policy->max %u\n", > policy->cpuinfo.max_freq, policy->max); > > - cpu = all_cpu_data[0]; > + cpu = all_cpu_data[policy->cpu]; > if (cpu->pstate.max_pstate_physical > cpu->pstate.max_pstate > && > policy->max < policy->cpuinfo.max_freq && > policy->max > cpu->pstate.max_pstate * cpu- > >pstate.scaling) { > @@ -1529,6 +1541,15 @@ static int intel_pstate_set_policy(struc > limits->max_perf = round_up(limits->max_perf, FRAC_BITS); > > out: > + if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) { > + /* > + * NOHZ_FULL CPUs need this as the governor callback > may not > + * be invoked on them. > + */ > + intel_pstate_clear_update_util_hook(policy->cpu); > + intel_pstate_max_within_limits(cpu); > + } > + > intel_pstate_set_update_util_hook(policy->cpu); > > intel_pstate_hwp_set_policy(policy); > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -1137,10 +1137,8 @@ static void intel_pstate_get_min_max(str *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf); } -static void intel_pstate_set_min_pstate(struct cpudata *cpu) +static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate) { - int pstate = cpu->pstate.min_pstate; - trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu); cpu->pstate.current_pstate = pstate; /* @@ -1152,6 +1150,20 @@ static void intel_pstate_set_min_pstate( pstate_funcs.get_val(cpu, pstate)); } +static void intel_pstate_set_min_pstate(struct cpudata *cpu) +{ + intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate); +} + +static void intel_pstate_max_within_limits(struct cpudata *cpu) +{ + int min_pstate, max_pstate; + + update_turbo_state(); + intel_pstate_get_min_max(cpu, &min_pstate, &max_pstate); + intel_pstate_set_pstate(cpu, max_pstate); +} + static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) { cpu->pstate.min_pstate = pstate_funcs.get_min(); @@ -1485,7 +1497,7 @@ static int intel_pstate_set_policy(struc pr_debug("set_policy cpuinfo.max %u policy->max %u\n", policy->cpuinfo.max_freq, policy->max); - cpu = all_cpu_data[0]; + cpu = all_cpu_data[policy->cpu]; if (cpu->pstate.max_pstate_physical > cpu->pstate.max_pstate && policy->max < policy->cpuinfo.max_freq && policy->max > cpu->pstate.max_pstate * cpu->pstate.scaling) { @@ -1529,6 +1541,15 @@ static int intel_pstate_set_policy(struc limits->max_perf = round_up(limits->max_perf, FRAC_BITS); out: + if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) { + /* + * NOHZ_FULL CPUs need this as the governor callback may not + * be invoked on them. + */ + intel_pstate_clear_update_util_hook(policy->cpu); + intel_pstate_max_within_limits(cpu); + } + intel_pstate_set_update_util_hook(policy->cpu); intel_pstate_hwp_set_policy(policy);