* [PATCH] intel_pstate: Improve initial busy calculation [not found] <1917099.8KOhsjZWCp@vostro.rjw.lan> @ 2014-05-30 17:10 ` dirk.brandewie 2014-05-30 21:35 ` Rafael J. Wysocki 0 siblings, 1 reply; 3+ messages in thread From: dirk.brandewie @ 2014-05-30 17:10 UTC (permalink / raw) To: linux-pm; +Cc: dirk.brandewie, rjw, dsmythies, stable, Dirk Brandewie From: Doug Smythies <dsmythies@telus.net> This change makes the busy calculation using 64 bit math which prevents overflow for large values of aperf/mperf. Cc: <stable@vger.kernel.org> # 3.14.x Signed-off-by: Doug Smythies <dsmythies@telus.net> Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> --- drivers/cpufreq/intel_pstate.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 032efe4f7..c034cde 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -563,16 +563,19 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) static inline void intel_pstate_calc_busy(struct cpudata *cpu, struct sample *sample) { - int32_t core_pct; + int64_t core_pct; + int32_t rem; - core_pct = div_fp(int_tofp((sample->aperf)), - int_tofp((sample->mperf))); - core_pct = mul_fp(core_pct, int_tofp(100)); + core_pct = int_tofp(sample->aperf) * int_tofp(100); + core_pct = div_u64_rem(core_pct, int_tofp(sample->mperf), &rem); + + if ((rem << 1) >= int_tofp((sample->mperf))) + core_pct += 1; sample->freq = fp_toint( mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct)); - sample->core_pct_busy = core_pct; + sample->core_pct_busy = (int32_t)core_pct; } static inline void intel_pstate_sample(struct cpudata *cpu) -- 1.9.0 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] intel_pstate: Improve initial busy calculation 2014-05-30 17:10 ` [PATCH] intel_pstate: Improve initial busy calculation dirk.brandewie @ 2014-05-30 21:35 ` Rafael J. Wysocki 2014-05-30 21:41 ` Rafael J. Wysocki 0 siblings, 1 reply; 3+ messages in thread From: Rafael J. Wysocki @ 2014-05-30 21:35 UTC (permalink / raw) To: dirk.brandewie, Dirk Brandewie; +Cc: linux-pm, dsmythies On Friday, May 30, 2014 10:10:57 AM dirk.brandewie@gmail.com wrote: > From: Doug Smythies <dsmythies@telus.net> > > This change makes the busy calculation using 64 bit math which prevents > overflow for large values of aperf/mperf. > > Cc: <stable@vger.kernel.org> # 3.14.x > Signed-off-by: Doug Smythies <dsmythies@telus.net> > Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> This doesn't apply for me on top of bleeding-edge. Is there a patch missing? Rafael > --- > drivers/cpufreq/intel_pstate.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index 032efe4f7..c034cde 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -563,16 +563,19 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) > static inline void intel_pstate_calc_busy(struct cpudata *cpu, > struct sample *sample) > { > - int32_t core_pct; > + int64_t core_pct; > + int32_t rem; > > - core_pct = div_fp(int_tofp((sample->aperf)), > - int_tofp((sample->mperf))); > - core_pct = mul_fp(core_pct, int_tofp(100)); > + core_pct = int_tofp(sample->aperf) * int_tofp(100); > + core_pct = div_u64_rem(core_pct, int_tofp(sample->mperf), &rem); > + > + if ((rem << 1) >= int_tofp((sample->mperf))) > + core_pct += 1; > > sample->freq = fp_toint( > mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct)); > > - sample->core_pct_busy = core_pct; > + sample->core_pct_busy = (int32_t)core_pct; > } > > static inline void intel_pstate_sample(struct cpudata *cpu) > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] intel_pstate: Improve initial busy calculation 2014-05-30 21:35 ` Rafael J. Wysocki @ 2014-05-30 21:41 ` Rafael J. Wysocki 0 siblings, 0 replies; 3+ messages in thread From: Rafael J. Wysocki @ 2014-05-30 21:41 UTC (permalink / raw) To: dirk.brandewie; +Cc: Dirk Brandewie, linux-pm, dsmythies On Friday, May 30, 2014 11:35:57 PM Rafael J. Wysocki wrote: > On Friday, May 30, 2014 10:10:57 AM dirk.brandewie@gmail.com wrote: > > From: Doug Smythies <dsmythies@telus.net> > > > > This change makes the busy calculation using 64 bit math which prevents > > overflow for large values of aperf/mperf. > > > > Cc: <stable@vger.kernel.org> # 3.14.x > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> > > This doesn't apply for me on top of bleeding-edge. Is there a patch missing? The one below does apply, however. Is that what you meant? --- drivers/cpufreq/intel_pstate.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 032efe4f7..c034cde 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -563,15 +563,19 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) static inline void intel_pstate_calc_busy(struct cpudata *cpu) { struct sample *sample = &cpu->sample; - int32_t core_pct; + int64_t core_pct; + int32_t rem; - core_pct = div_fp(int_tofp(sample->aperf), int_tofp(sample->mperf)); - core_pct = mul_fp(core_pct, int_tofp(100)); + core_pct = int_tofp(sample->aperf) * int_tofp(100); + core_pct = div_u64_rem(core_pct, int_tofp(sample->mperf), &rem); + + if ((rem << 1) >= int_tofp(sample->mperf)) + core_pct += 1; sample->freq = fp_toint( mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct)); - sample->core_pct_busy = core_pct; + sample->core_pct_busy = (int32_t)core_pct; } static inline void intel_pstate_sample(struct cpudata *cpu) ^ permalink raw reply related [flat|nested] 3+ messages in thread
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2014-05-30 17:10 ` [PATCH] intel_pstate: Improve initial busy calculation dirk.brandewie
2014-05-30 21:35 ` Rafael J. Wysocki
2014-05-30 21:41 ` Rafael J. Wysocki
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