Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752460AbaFJQ1C (ORCPT ); Tue, 10 Jun 2014 12:27:02 -0400 Received: from sema.semaphore.gr ([78.46.194.137]:57421 "EHLO sema.semaphore.gr" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751063AbaFJQ1A (ORCPT ); Tue, 10 Jun 2014 12:27:00 -0400 Message-ID: <539731D1.6040504@semaphore.gr> Date: Tue, 10 Jun 2014 19:26:57 +0300 From: Stratos Karafotis User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Dirk Brandewie , "Rafael J. Wysocki" , Viresh Kumar , Dirk Brandewie CC: "linux-pm@vger.kernel.org" , LKML Subject: Re: [PATCH 2/7] cpufreq: intel_pstate: Avoid duplicate call of intel_pstate_get_scaled_busy References: <53962067.4060504@semaphore.gr> <53972CE1.1060209@gmail.com> In-Reply-To: <53972CE1.1060209@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/06/2014 07:05 μμ, Dirk Brandewie wrote: > On 06/09/2014 02:00 PM, Stratos Karafotis wrote: >> Store busy_scaled value to avoid to duplicate call of >> intel_pstate_get_scaled_busy on every sampling interval. >> > > The second call *only* happens if the tracepoint is being used otherwise > the whole function call to trace_pstate_sample() is a noop. Yes, I'm sorry, I forgot to add this in my changelog. I have written this in cover letter. I made this change mostly to support patch 3/7. > This makes the code less readable IMHO the reader is left wondering > how cpu->sample.busy_scaled was set in intel_pstate_adjust_busy_pstate() > I agree that the the original code is more readable. If we don't care about the small overhead when tracing is on and forget patch 3/7, of course the original code is by far better. >> Also, rename the function to intel_pstate_calc_scaled_busy. >> >> Signed-off-by: Stratos Karafotis >> --- >> drivers/cpufreq/intel_pstate.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c >> index 4e7f492..31e2ae5 100644 >> --- a/drivers/cpufreq/intel_pstate.c >> +++ b/drivers/cpufreq/intel_pstate.c >> @@ -55,6 +55,7 @@ static inline int32_t div_fp(int32_t x, int32_t y) >> >> struct sample { >> int32_t core_pct_busy; >> + int32_t busy_scaled; >> u64 aperf; >> u64 mperf; >> int freq; >> @@ -604,7 +605,7 @@ static inline void intel_pstate_set_sample_time(struct cpudata *cpu) >> mod_timer_pinned(&cpu->timer, jiffies + delay); >> } >> >> -static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu) >> +static inline void intel_pstate_calc_scaled_busy(struct cpudata *cpu) >> { >> int32_t core_busy, max_pstate, current_pstate, sample_ratio; >> u32 duration_us; >> @@ -624,20 +625,19 @@ static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu) >> core_busy = mul_fp(core_busy, sample_ratio); >> } >> >> - return core_busy; >> + cpu->sample.busy_scaled = core_busy; >> } >> >> static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu) >> { >> - int32_t busy_scaled; >> struct _pid *pid; >> signed int ctl = 0; >> int steps; >> >> pid = &cpu->pid; >> - busy_scaled = intel_pstate_get_scaled_busy(cpu); >> + intel_pstate_calc_scaled_busy(cpu); >> >> - ctl = pid_calc(pid, busy_scaled); >> + ctl = pid_calc(pid, cpu->sample.busy_scaled); >> >> steps = abs(ctl); >> >> @@ -659,7 +659,7 @@ static void intel_pstate_timer_func(unsigned long __data) >> intel_pstate_adjust_busy_pstate(cpu); >> >> trace_pstate_sample(fp_toint(sample->core_pct_busy), >> - fp_toint(intel_pstate_get_scaled_busy(cpu)), >> + fp_toint(sample->busy_scaled), >> cpu->pstate.current_pstate, >> sample->mperf, >> sample->aperf, >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/