Re: [PATCH 1/2] cpufreq: intel_pstate: Clean up after performance governor changes

[Srinivas Pandruvada]

On Thu, 2017-06-29 at 01:47 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> 
> After commit 82b4e03e01bc (intel_pstate: skip scheduler hook when in
> "performance" mode) get_target_pstate_use_performance() and
> get_target_pstate_use_cpu_load() are never called if scaling_governor
> is "performance", so drop the CPUFREQ_POLICY_PERFORMANCE checks from
> them as they will never trigger anyway.
> 
> Moreover, the documentation needs to be updated to reflect the change
> made by the above commit, so do that too.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>

> ---
> ÂDocumentation/admin-guide/pm/intel_pstate.rst |ÂÂÂÂ6 ++----
> Âdrivers/cpufreq/intel_pstate.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂ6 ------
> Â2 files changed, 2 insertions(+), 10 deletions(-)
> 
> Index: linux-pm/drivers/cpufreq/intel_pstate.c
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/intel_pstate.c
> +++ linux-pm/drivers/cpufreq/intel_pstate.c
> @@ -1612,9 +1612,6 @@ static inline int32_t get_target_pstate_
> Â	int32_t busy_frac, boost;
> Â	int target, avg_pstate;
> Â
> -	if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE)
> -		return cpu->pstate.turbo_pstate;
> -
> Â	busy_frac = div_fp(sample->mperf, sample->tsc);
> Â
> Â	boost = cpu->iowait_boost;
> @@ -1651,9 +1648,6 @@ static inline int32_t get_target_pstate_
> Â	int32_t perf_scaled, max_pstate, current_pstate,
> sample_ratio;
> Â	u64 duration_ns;
> Â
> -	if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE)
> -		return cpu->pstate.turbo_pstate;
> -
> Â	/*
> Â	Â* perf_scaled is the ratio of the average P-state during
> the last
> Â	Â* sampling period to the P-state requested last time (in
> percent).
> Index: linux-pm/Documentation/admin-guide/pm/intel_pstate.rst
> ===================================================================
> --- linux-pm.orig/Documentation/admin-guide/pm/intel_pstate.rst
> +++ linux-pm/Documentation/admin-guide/pm/intel_pstate.rst
> @@ -157,10 +157,8 @@ Without HWP, this P-state selection algo
> Âthe processor model and platform configuration.
> Â
> ÂIt selects the maximum P-state it is allowed to use, subject to
> limits set via
> -``sysfs``, every time the P-state selection computations are carried
> out by the
> -driver's utilization update callback for the given CPU (that does
> not happen
> -more often than every 10 ms), but the hardware configuration will
> not be changed
> -if the new P-state is the same as the current one.
> +``sysfs``, every time the driver configuration for the given CPU is
> updated
> +(e.g. via ``sysfs``).
> Â
> ÂThis is the default P-state selection algorithm if the
> Â:c:macro:`CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE` kernel
> configuration option
>