| Message ID | 1579083620-24943-1-git-send-email-vincent.guittot@linaro.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | sched/fair: remove redundant call to cpufreq_update_util | expand |
On Wednesday, January 15, 2020 11:20:20 AM CET Vincent Guittot wrote: > With commit bef69dd87828 ("sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()") > update_load_avg() has become the central point for calling cpufreq (not > including the update of blocked load). This change helps to simplify > further the number of call to cpufreq_update_util() and to remove last s/call/calls/ And the patch looks reasonable to me. > redundant ones. With update_load_avg(), we are now sure that > cpufreq_update_util() will be called after every task attachment to a > cfs_rq and especially after propagating this event down to the util_avg of > the root cfs_rq, which is the level that is used by cpufreq governors like > schedutil to set the frequency of a CPU. > > The SCHED_CPUFREQ_MIGRATION flag forces an early call to cpufreq when the > migration happens in a cgroup whereas util_avg of root cfs_rq is not yet > updated and this call is duplicated with the one that happens immediately > after when the migration event reaches the root cfs_rq. The dedicated flag > SCHED_CPUFREQ_MIGRATION is now useless and can be removed. The interface of > attach_entity_load_avg() can also be simplified accordingly. > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > include/linux/sched/cpufreq.h | 1 - > kernel/sched/fair.c | 14 +++++++------- > 2 files changed, 7 insertions(+), 8 deletions(-) > > diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h > index cc6bcc1e96bc..3ed5aa18593f 100644 > --- a/include/linux/sched/cpufreq.h > +++ b/include/linux/sched/cpufreq.h > @@ -9,7 +9,6 @@ > */ > > #define SCHED_CPUFREQ_IOWAIT (1U << 0) > -#define SCHED_CPUFREQ_MIGRATION (1U << 1) > > #ifdef CONFIG_CPU_FREQ > struct cpufreq_policy; > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 2d170b5da0e3..023aa42aaac7 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -801,7 +801,7 @@ void post_init_entity_util_avg(struct task_struct *p) > * For !fair tasks do: > * > update_cfs_rq_load_avg(now, cfs_rq); > - attach_entity_load_avg(cfs_rq, se, 0); > + attach_entity_load_avg(cfs_rq, se); > switched_from_fair(rq, p); > * > * such that the next switched_to_fair() has the > @@ -3114,7 +3114,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq, int flags) > { > struct rq *rq = rq_of(cfs_rq); > > - if (&rq->cfs == cfs_rq || (flags & SCHED_CPUFREQ_MIGRATION)) { > + if (&rq->cfs == cfs_rq) { > /* > * There are a few boundary cases this might miss but it should > * get called often enough that that should (hopefully) not be > @@ -3520,7 +3520,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) > * Must call update_cfs_rq_load_avg() before this, since we rely on > * cfs_rq->avg.last_update_time being current. > */ > -static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) > +static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) > { > u32 divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib; > > @@ -3556,7 +3556,7 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s > > add_tg_cfs_propagate(cfs_rq, se->avg.load_sum); > > - cfs_rq_util_change(cfs_rq, flags); > + cfs_rq_util_change(cfs_rq, 0); > > trace_pelt_cfs_tp(cfs_rq); > } > @@ -3614,7 +3614,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s > * > * IOW we're enqueueing a task on a new CPU. > */ > - attach_entity_load_avg(cfs_rq, se, SCHED_CPUFREQ_MIGRATION); > + attach_entity_load_avg(cfs_rq, se); > update_tg_load_avg(cfs_rq, 0); > > } else if (decayed) { > @@ -3871,7 +3871,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s > static inline void remove_entity_load_avg(struct sched_entity *se) {} > > static inline void > -attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) {} > +attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} > static inline void > detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} > > @@ -10439,7 +10439,7 @@ static void attach_entity_cfs_rq(struct sched_entity *se) > > /* Synchronize entity with its cfs_rq */ > update_load_avg(cfs_rq, se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD); > - attach_entity_load_avg(cfs_rq, se, 0); > + attach_entity_load_avg(cfs_rq, se); > update_tg_load_avg(cfs_rq, false); > propagate_entity_cfs_rq(se); > } >
On Wed, Jan 15, 2020 at 11:20:20AM +0100, Vincent Guittot wrote: > With commit bef69dd87828 ("sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()") > update_load_avg() has become the central point for calling cpufreq (not > including the update of blocked load). This change helps to simplify > further the number of call to cpufreq_update_util() and to remove last > redundant ones. With update_load_avg(), we are now sure that > cpufreq_update_util() will be called after every task attachment to a > cfs_rq and especially after propagating this event down to the util_avg of > the root cfs_rq, which is the level that is used by cpufreq governors like > schedutil to set the frequency of a CPU. > > The SCHED_CPUFREQ_MIGRATION flag forces an early call to cpufreq when the > migration happens in a cgroup whereas util_avg of root cfs_rq is not yet > updated and this call is duplicated with the one that happens immediately > after when the migration event reaches the root cfs_rq. The dedicated flag > SCHED_CPUFREQ_MIGRATION is now useless and can be removed. The interface of > attach_entity_load_avg() can also be simplified accordingly. > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Thanks!
On 15/01/2020 11:20, Vincent Guittot wrote: > With commit bef69dd87828 ("sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()") > update_load_avg() has become the central point for calling cpufreq (not > including the update of blocked load). This change helps to simplify > further the number of call to cpufreq_update_util() and to remove last > redundant ones. With update_load_avg(), we are now sure that > cpufreq_update_util() will be called after every task attachment to a > cfs_rq and especially after propagating this event down to the util_avg of > the root cfs_rq, which is the level that is used by cpufreq governors like > schedutil to set the frequency of a CPU. > > The SCHED_CPUFREQ_MIGRATION flag forces an early call to cpufreq when the > migration happens in a cgroup whereas util_avg of root cfs_rq is not yet > updated and this call is duplicated with the one that happens immediately > after when the migration event reaches the root cfs_rq. The dedicated flag > SCHED_CPUFREQ_MIGRATION is now useless and can be removed. The interface of > attach_entity_load_avg() can also be simplified accordingly. > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> LGTM. Doesn't this allow to get rid of the 'int flags' in cfs_rq_util_change() as well? 8<--- kernel/sched/fair.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 328d59e8afba..f82f4fde0cd3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3110,7 +3110,7 @@ static inline void update_cfs_group(struct sched_entity *se) } #endif /* CONFIG_FAIR_GROUP_SCHED */ -static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq, int flags) +static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq) { struct rq *rq = rq_of(cfs_rq); @@ -3129,7 +3129,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq, int flags) * * See cpu_util(). */ - cpufreq_update_util(rq, flags); + cpufreq_update_util(rq, 0); } } @@ -3556,7 +3556,7 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s add_tg_cfs_propagate(cfs_rq, se->avg.load_sum); - cfs_rq_util_change(cfs_rq, 0); + cfs_rq_util_change(cfs_rq); trace_pelt_cfs_tp(cfs_rq); } @@ -3577,7 +3577,7 @@ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s add_tg_cfs_propagate(cfs_rq, -se->avg.load_sum); - cfs_rq_util_change(cfs_rq, 0); + cfs_rq_util_change(cfs_rq); trace_pelt_cfs_tp(cfs_rq); } @@ -3618,7 +3618,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s update_tg_load_avg(cfs_rq, 0); } else if (decayed) { - cfs_rq_util_change(cfs_rq, 0); + cfs_rq_util_change(cfs_rq); if (flags & UPDATE_TG) update_tg_load_avg(cfs_rq, 0); @@ -3851,7 +3851,7 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq) static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int not_used1) { - cfs_rq_util_change(cfs_rq, 0); + cfs_rq_util_change(cfs_rq); } static inline void remove_entity_load_avg(struct sched_entity *se) {}
On Wed, 15 Jan 2020 at 21:20, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote: > > On 15/01/2020 11:20, Vincent Guittot wrote: > > With commit bef69dd87828 ("sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()") > > update_load_avg() has become the central point for calling cpufreq (not > > including the update of blocked load). This change helps to simplify > > further the number of call to cpufreq_update_util() and to remove last > > redundant ones. With update_load_avg(), we are now sure that > > cpufreq_update_util() will be called after every task attachment to a > > cfs_rq and especially after propagating this event down to the util_avg of > > the root cfs_rq, which is the level that is used by cpufreq governors like > > schedutil to set the frequency of a CPU. > > > > The SCHED_CPUFREQ_MIGRATION flag forces an early call to cpufreq when the > > migration happens in a cgroup whereas util_avg of root cfs_rq is not yet > > updated and this call is duplicated with the one that happens immediately > > after when the migration event reaches the root cfs_rq. The dedicated flag > > SCHED_CPUFREQ_MIGRATION is now useless and can be removed. The interface of > > attach_entity_load_avg() can also be simplified accordingly. > > > > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> > > LGTM. Doesn't this allow to get rid of the 'int flags' in > cfs_rq_util_change() as well? I asked myself the same question but decided to keep the same interface as cpufreq_update_util > > 8<--- > > kernel/sched/fair.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 328d59e8afba..f82f4fde0cd3 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3110,7 +3110,7 @@ static inline void update_cfs_group(struct sched_entity *se) > } > #endif /* CONFIG_FAIR_GROUP_SCHED */ > > -static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq, int flags) > +static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq) > { > struct rq *rq = rq_of(cfs_rq); > > @@ -3129,7 +3129,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq, int flags) > * > * See cpu_util(). > */ > - cpufreq_update_util(rq, flags); > + cpufreq_update_util(rq, 0); > } > } > > @@ -3556,7 +3556,7 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s > > add_tg_cfs_propagate(cfs_rq, se->avg.load_sum); > > - cfs_rq_util_change(cfs_rq, 0); > + cfs_rq_util_change(cfs_rq); > > trace_pelt_cfs_tp(cfs_rq); > } > @@ -3577,7 +3577,7 @@ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s > > add_tg_cfs_propagate(cfs_rq, -se->avg.load_sum); > > - cfs_rq_util_change(cfs_rq, 0); > + cfs_rq_util_change(cfs_rq); > > trace_pelt_cfs_tp(cfs_rq); > } > @@ -3618,7 +3618,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s > update_tg_load_avg(cfs_rq, 0); > > } else if (decayed) { > - cfs_rq_util_change(cfs_rq, 0); > + cfs_rq_util_change(cfs_rq); > > if (flags & UPDATE_TG) > update_tg_load_avg(cfs_rq, 0); > @@ -3851,7 +3851,7 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq) > > static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int not_used1) > { > - cfs_rq_util_change(cfs_rq, 0); > + cfs_rq_util_change(cfs_rq); > } > > static inline void remove_entity_load_avg(struct sched_entity *se) {} > -- > 2.17.1
diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h index cc6bcc1e96bc..3ed5aa18593f 100644 --- a/include/linux/sched/cpufreq.h +++ b/include/linux/sched/cpufreq.h @@ -9,7 +9,6 @@ */ #define SCHED_CPUFREQ_IOWAIT (1U << 0) -#define SCHED_CPUFREQ_MIGRATION (1U << 1) #ifdef CONFIG_CPU_FREQ struct cpufreq_policy; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2d170b5da0e3..023aa42aaac7 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -801,7 +801,7 @@ void post_init_entity_util_avg(struct task_struct *p) * For !fair tasks do: * update_cfs_rq_load_avg(now, cfs_rq); - attach_entity_load_avg(cfs_rq, se, 0); + attach_entity_load_avg(cfs_rq, se); switched_from_fair(rq, p); * * such that the next switched_to_fair() has the @@ -3114,7 +3114,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq, int flags) { struct rq *rq = rq_of(cfs_rq); - if (&rq->cfs == cfs_rq || (flags & SCHED_CPUFREQ_MIGRATION)) { + if (&rq->cfs == cfs_rq) { /* * There are a few boundary cases this might miss but it should * get called often enough that that should (hopefully) not be @@ -3520,7 +3520,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) * Must call update_cfs_rq_load_avg() before this, since we rely on * cfs_rq->avg.last_update_time being current. */ -static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) +static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { u32 divider = LOAD_AVG_MAX - 1024 + cfs_rq->avg.period_contrib; @@ -3556,7 +3556,7 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s add_tg_cfs_propagate(cfs_rq, se->avg.load_sum); - cfs_rq_util_change(cfs_rq, flags); + cfs_rq_util_change(cfs_rq, 0); trace_pelt_cfs_tp(cfs_rq); } @@ -3614,7 +3614,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s * * IOW we're enqueueing a task on a new CPU. */ - attach_entity_load_avg(cfs_rq, se, SCHED_CPUFREQ_MIGRATION); + attach_entity_load_avg(cfs_rq, se); update_tg_load_avg(cfs_rq, 0); } else if (decayed) { @@ -3871,7 +3871,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s static inline void remove_entity_load_avg(struct sched_entity *se) {} static inline void -attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) {} +attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} static inline void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {} @@ -10439,7 +10439,7 @@ static void attach_entity_cfs_rq(struct sched_entity *se) /* Synchronize entity with its cfs_rq */ update_load_avg(cfs_rq, se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD); - attach_entity_load_avg(cfs_rq, se, 0); + attach_entity_load_avg(cfs_rq, se); update_tg_load_avg(cfs_rq, false); propagate_entity_cfs_rq(se); }
With commit bef69dd87828 ("sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()") update_load_avg() has become the central point for calling cpufreq (not including the update of blocked load). This change helps to simplify further the number of call to cpufreq_update_util() and to remove last redundant ones. With update_load_avg(), we are now sure that cpufreq_update_util() will be called after every task attachment to a cfs_rq and especially after propagating this event down to the util_avg of the root cfs_rq, which is the level that is used by cpufreq governors like schedutil to set the frequency of a CPU. The SCHED_CPUFREQ_MIGRATION flag forces an early call to cpufreq when the migration happens in a cgroup whereas util_avg of root cfs_rq is not yet updated and this call is duplicated with the one that happens immediately after when the migration event reaches the root cfs_rq. The dedicated flag SCHED_CPUFREQ_MIGRATION is now useless and can be removed. The interface of attach_entity_load_avg() can also be simplified accordingly. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> --- include/linux/sched/cpufreq.h | 1 - kernel/sched/fair.c | 14 +++++++------- 2 files changed, 7 insertions(+), 8 deletions(-)