| Message ID | 1409051215-16788-5-git-send-email-vincent.guittot@linaro.org |
|---|---|
| State | New |
| Headers | show |
* Vincent Guittot <vincent.guittot@linaro.org> [2014-08-26 13:06:47]: > capacity_orig is only changed for system with a SMT sched_domain level in order > to reflect the lower capacity of CPUs. Heterogenous system also have to reflect an > original capacity that is different from the default value. > > Create a more generic function arch_scale_cpu_capacity that can be also used by > non SMT platform to set capacity_orig. > > The weak behavior of arch_scale_cpu_capacity is the previous SMT one in order to > keep backward compatibility in the use of capacity_orig. > > arch_scale_smt_capacity and default_scale_smt_capacity have been removed as > they were not use elsewhere than in arch_scale_cpu_capacity. > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> -- 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/
Hi Vincent, On 08/26/2014 04:36 PM, Vincent Guittot wrote: > capacity_orig is only changed for system with a SMT sched_domain level in order I think I had asked this before, but why only capacity_orig? The capacity of a group is also being updated the same way. This patch fixes the capacity of a group to reflect the capacity of the heterogeneous CPUs in it, this capacity being both the full capacity of the group: capacity_orig and the capacity available for the fair tasks. So I feel in the subject as well as the changelog it would suffice to say 'capacity'. > to reflect the lower capacity of CPUs. Heterogenous system also have to reflect an > original capacity that is different from the default value. > > Create a more generic function arch_scale_cpu_capacity that can be also used by > non SMT platform to set capacity_orig. > > The weak behavior of arch_scale_cpu_capacity is the previous SMT one in order to > keep backward compatibility in the use of capacity_orig. > > arch_scale_smt_capacity and default_scale_smt_capacity have been removed as > they were not use elsewhere than in arch_scale_cpu_capacity. > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> > --- > kernel/sched/fair.c | 25 ++++++------------------- > 1 file changed, 6 insertions(+), 19 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index b85e9f7..8176bda 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5705,19 +5705,12 @@ unsigned long __weak arch_scale_freq_capacity(struct sched_domain *sd, int cpu) > return default_scale_capacity(sd, cpu); > } > > -static unsigned long default_scale_smt_capacity(struct sched_domain *sd, int cpu) > +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) > { > - unsigned long weight = sd->span_weight; > - unsigned long smt_gain = sd->smt_gain; > + if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) > + return sd->smt_gain / sd->span_weight; > > - smt_gain /= weight; > - > - return smt_gain; > -} > - > -unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu) > -{ > - return default_scale_smt_capacity(sd, cpu); > + return SCHED_CAPACITY_SCALE; > } > > static unsigned long scale_rt_capacity(int cpu) > @@ -5756,18 +5749,12 @@ static unsigned long scale_rt_capacity(int cpu) > > static void update_cpu_capacity(struct sched_domain *sd, int cpu) > { > - unsigned long weight = sd->span_weight; > unsigned long capacity = SCHED_CAPACITY_SCALE; > struct sched_group *sdg = sd->groups; > > - if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { > - if (sched_feat(ARCH_CAPACITY)) Aren't you missing this check above? I understand that it is not crucial, but that would also mean removing ARCH_CAPACITY sched_feat altogether, wouldn't it? Regards Preeti U Murthy > - capacity *= arch_scale_smt_capacity(sd, cpu); > - else > - capacity *= default_scale_smt_capacity(sd, cpu); > + capacity *= arch_scale_cpu_capacity(sd, cpu); > > - capacity >>= SCHED_CAPACITY_SHIFT; > - } > + capacity >>= SCHED_CAPACITY_SHIFT; > > sdg->sgc->capacity_orig = capacity; > -- 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/
On 30 August 2014 19:07, Preeti U Murthy <preeti@linux.vnet.ibm.com> wrote: > Hi Vincent, > > On 08/26/2014 04:36 PM, Vincent Guittot wrote: >> capacity_orig is only changed for system with a SMT sched_domain level in order > > I think I had asked this before, but why only capacity_orig? The > capacity of a group is also being updated the same way. This patch fixes > the capacity of a group to reflect the capacity of the heterogeneous > CPUs in it, this capacity being both the full capacity of the group: > capacity_orig and the capacity available for the fair tasks. So I feel > in the subject as well as the changelog it would suffice to say 'capacity'. IIRC, we discussed that point on a former version. The patch changes only the behavior of capacity_orig but the behavior of capacity stays unchanged as all archs can already set the capacity whereas the capacity_orig was configurable only if the SD_SHARE_CPUCAPACITY was set in the sched_domain. This is no more the case with this patch which creates arch_scale_cpu_capacity for setting capacity_orig. > >> to reflect the lower capacity of CPUs. Heterogenous system also have to reflect an >> original capacity that is different from the default value. >> >> Create a more generic function arch_scale_cpu_capacity that can be also used by >> non SMT platform to set capacity_orig. >> >> The weak behavior of arch_scale_cpu_capacity is the previous SMT one in order to >> keep backward compatibility in the use of capacity_orig. >> >> arch_scale_smt_capacity and default_scale_smt_capacity have been removed as >> they were not use elsewhere than in arch_scale_cpu_capacity. >> >> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> >> --- >> kernel/sched/fair.c | 25 ++++++------------------- >> 1 file changed, 6 insertions(+), 19 deletions(-) >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index b85e9f7..8176bda 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -5705,19 +5705,12 @@ unsigned long __weak arch_scale_freq_capacity(struct sched_domain *sd, int cpu) >> return default_scale_capacity(sd, cpu); >> } >> >> -static unsigned long default_scale_smt_capacity(struct sched_domain *sd, int cpu) >> +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) >> { >> - unsigned long weight = sd->span_weight; >> - unsigned long smt_gain = sd->smt_gain; >> + if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) >> + return sd->smt_gain / sd->span_weight; >> >> - smt_gain /= weight; >> - >> - return smt_gain; >> -} >> - >> -unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu) >> -{ >> - return default_scale_smt_capacity(sd, cpu); >> + return SCHED_CAPACITY_SCALE; >> } >> >> static unsigned long scale_rt_capacity(int cpu) >> @@ -5756,18 +5749,12 @@ static unsigned long scale_rt_capacity(int cpu) >> >> static void update_cpu_capacity(struct sched_domain *sd, int cpu) >> { >> - unsigned long weight = sd->span_weight; >> unsigned long capacity = SCHED_CAPACITY_SCALE; >> struct sched_group *sdg = sd->groups; >> >> - if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { >> - if (sched_feat(ARCH_CAPACITY)) > > Aren't you missing this check above? I understand that it is not > crucial, but that would also mean removing ARCH_CAPACITY sched_feat > altogether, wouldn't it? Peter has proposed to remove all those checks and to keep only the default behavior because no arch uses arch_scale_smt_capacity. Then, ARCH_CAPACITY is still used in update_cpu_capacity Regards, Vincent > > Regards > Preeti U Murthy >> - capacity *= arch_scale_smt_capacity(sd, cpu); >> - else >> - capacity *= default_scale_smt_capacity(sd, cpu); >> + capacity *= arch_scale_cpu_capacity(sd, cpu); >> >> - capacity >>= SCHED_CAPACITY_SHIFT; >> - } >> + capacity >>= SCHED_CAPACITY_SHIFT; >> >> sdg->sgc->capacity_orig = capacity; >> > -- 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/
On 09/01/2014 01:35 PM, Vincent Guittot wrote: > On 30 August 2014 19:07, Preeti U Murthy <preeti@linux.vnet.ibm.com> wrote: >> Hi Vincent, >> >> On 08/26/2014 04:36 PM, Vincent Guittot wrote: >>> capacity_orig is only changed for system with a SMT sched_domain level in order >> >> I think I had asked this before, but why only capacity_orig? The >> capacity of a group is also being updated the same way. This patch fixes >> the capacity of a group to reflect the capacity of the heterogeneous >> CPUs in it, this capacity being both the full capacity of the group: >> capacity_orig and the capacity available for the fair tasks. So I feel >> in the subject as well as the changelog it would suffice to say 'capacity'. > > IIRC, we discussed that point on a former version. The patch changes > only the behavior of capacity_orig but the behavior of capacity stays > unchanged as all archs can already set the capacity whereas the > capacity_orig was configurable only if the SD_SHARE_CPUCAPACITY was > set in the sched_domain. This is no more the case with this patch > which creates arch_scale_cpu_capacity for setting capacity_orig. Yes, sorry I overlooked that. Reviewed-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Regards Preeti U Murthy -- 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/
On 10 September 2014 15:50, Peter Zijlstra <peterz@infradead.org> wrote: > On Sat, Aug 30, 2014 at 10:37:40PM +0530, Preeti U Murthy wrote: >> > - if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { >> > - if (sched_feat(ARCH_CAPACITY)) >> >> Aren't you missing this check above? I understand that it is not >> crucial, but that would also mean removing ARCH_CAPACITY sched_feat >> altogether, wouldn't it? > > Yes he's missing that, I added the below bit on top. FWIW, your changes are fine for me > > So the argument last time: > lkml.kernel.org/r/20140709105721.GT19379@twins.programming.kicks-ass.net > was that you cannot put sched_feat(ARCH_CAPACITY) inside a weak arch_* > function. The test has to be outside, seeing how it needs to decide to > call the arch function at all (or revert to the default implementation). > > --- > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5700,7 +5700,7 @@ unsigned long __weak arch_scale_freq_cap > return default_scale_capacity(sd, cpu); > } > > -unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) > +static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int cpu) > { > if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) > return sd->smt_gain / sd->span_weight; > @@ -5708,6 +5708,11 @@ unsigned long __weak arch_scale_cpu_capa > return SCHED_CAPACITY_SCALE; > } > > +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) > +{ > + return default_scale_cpu_capacity(sd, cpu); > +} > + > static unsigned long scale_rt_capacity(int cpu) > { > struct rq *rq = cpu_rq(cpu); > @@ -5747,7 +5752,10 @@ static void update_cpu_capacity(struct s > unsigned long capacity = SCHED_CAPACITY_SCALE; > struct sched_group *sdg = sd->groups; > > - capacity *= arch_scale_cpu_capacity(sd, cpu); > + if (sched_feat(ARCH_CAPACITY)) > + capacity *= arch_scale_cpu_capacity(sd, cpu); > + else > + capacity *= default_scale_cpu_capacity(sd, cpu); > > capacity >>= SCHED_CAPACITY_SHIFT; > -- 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/
On 09/10/2014 07:20 PM, Peter Zijlstra wrote: > On Sat, Aug 30, 2014 at 10:37:40PM +0530, Preeti U Murthy wrote: >>> - if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { >>> - if (sched_feat(ARCH_CAPACITY)) >> >> Aren't you missing this check above? I understand that it is not >> crucial, but that would also mean removing ARCH_CAPACITY sched_feat >> altogether, wouldn't it? > > Yes he's missing that, I added the below bit on top. > > So the argument last time: > lkml.kernel.org/r/20140709105721.GT19379@twins.programming.kicks-ass.net > was that you cannot put sched_feat(ARCH_CAPACITY) inside a weak arch_* > function. The test has to be outside, seeing how it needs to decide to > call the arch function at all (or revert to the default implementation). > > --- > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5700,7 +5700,7 @@ unsigned long __weak arch_scale_freq_cap > return default_scale_capacity(sd, cpu); > } > > -unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) > +static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int cpu) > { > if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) > return sd->smt_gain / sd->span_weight; > @@ -5708,6 +5708,11 @@ unsigned long __weak arch_scale_cpu_capa > return SCHED_CAPACITY_SCALE; > } > > +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) > +{ > + return default_scale_cpu_capacity(sd, cpu); > +} > + > static unsigned long scale_rt_capacity(int cpu) > { > struct rq *rq = cpu_rq(cpu); > @@ -5747,7 +5752,10 @@ static void update_cpu_capacity(struct s > unsigned long capacity = SCHED_CAPACITY_SCALE; > struct sched_group *sdg = sd->groups; > > - capacity *= arch_scale_cpu_capacity(sd, cpu); > + if (sched_feat(ARCH_CAPACITY)) > + capacity *= arch_scale_cpu_capacity(sd, cpu); > + else > + capacity *= default_scale_cpu_capacity(sd, cpu); > > capacity >>= SCHED_CAPACITY_SHIFT; > > Alright, I see now. Thanks! Regards Preeti U Murthy -- 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/
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b85e9f7..8176bda 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5705,19 +5705,12 @@ unsigned long __weak arch_scale_freq_capacity(struct sched_domain *sd, int cpu) return default_scale_capacity(sd, cpu); } -static unsigned long default_scale_smt_capacity(struct sched_domain *sd, int cpu) +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) { - unsigned long weight = sd->span_weight; - unsigned long smt_gain = sd->smt_gain; + if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) + return sd->smt_gain / sd->span_weight; - smt_gain /= weight; - - return smt_gain; -} - -unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu) -{ - return default_scale_smt_capacity(sd, cpu); + return SCHED_CAPACITY_SCALE; } static unsigned long scale_rt_capacity(int cpu) @@ -5756,18 +5749,12 @@ static unsigned long scale_rt_capacity(int cpu) static void update_cpu_capacity(struct sched_domain *sd, int cpu) { - unsigned long weight = sd->span_weight; unsigned long capacity = SCHED_CAPACITY_SCALE; struct sched_group *sdg = sd->groups; - if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { - if (sched_feat(ARCH_CAPACITY)) - capacity *= arch_scale_smt_capacity(sd, cpu); - else - capacity *= default_scale_smt_capacity(sd, cpu); + capacity *= arch_scale_cpu_capacity(sd, cpu); - capacity >>= SCHED_CAPACITY_SHIFT; - } + capacity >>= SCHED_CAPACITY_SHIFT; sdg->sgc->capacity_orig = capacity;
capacity_orig is only changed for system with a SMT sched_domain level in order to reflect the lower capacity of CPUs. Heterogenous system also have to reflect an original capacity that is different from the default value. Create a more generic function arch_scale_cpu_capacity that can be also used by non SMT platform to set capacity_orig. The weak behavior of arch_scale_cpu_capacity is the previous SMT one in order to keep backward compatibility in the use of capacity_orig. arch_scale_smt_capacity and default_scale_smt_capacity have been removed as they were not use elsewhere than in arch_scale_cpu_capacity. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> --- kernel/sched/fair.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-)