On 04/20/20 10:29, Dietmar Eggemann wrote: > On 03.04.20 14:30, Qais Yousef wrote: > > [...] > > > @@ -924,6 +945,14 @@ uclamp_eff_get(struct task_struct *p, enum uclamp_id clamp_id) > > return uc_req; > > } > > > > +static void uclamp_rt_sync_default_util_min(struct task_struct *p) > > +{ > > + struct uclamp_se *uc_se = &p->uclamp_req[UCLAMP_MIN]; > > + > > + if (!uc_se->user_defined) > > + uclamp_se_set(uc_se, sysctl_sched_rt_default_uclamp_util_min, false); > > +} > > + > > unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id) > > { > > struct uclamp_se uc_eff; > > @@ -1030,6 +1059,12 @@ static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) > > if (unlikely(!p->sched_class->uclamp_enabled)) > > return; > > > > + /* > > + * When sysctl_sched_rt_default_uclamp_util_min value is changed by the > > + * user, we apply any new value on the next wakeup, which is here. > > + */ > > + uclamp_rt_sync_default_util_min(p); > > + > > Does this have to be an extra function? Can we not reuse > uclamp_tg_restrict() by slightly rename it to uclamp_restrict()? Hmm the thing is that we're not restricting here. In contrary we're boosting, so the name would be misleading. > > This function will then deal with enforcing restrictions, whether system > and taskgroup hierarchy related or default value (latter only for rt-min > right now since the others are fixed) related. > > uclamp_eff_get() -> uclamp_restrict() is called from: > > 'enqueue_task(), uclamp_update_active() -> uclamp_rq_inc() -> uclamp_rq_inc_id()' and > > 'task_fits_capacity() -> clamp_task_util(), rt_task_fits_capacity() -> uclamp_eff_value()' and > > 'schedutil_cpu_util(), find_energy_efficient_cpu() -> uclamp_rq_util_with() -> uclamp_eff_value()' > > so there would be more check-points than the one in 'enqueue_task() -> uclamp_rq_inc()' now. I think you're revolving around the same idea that Patrick was suggesting. I think it is possible to do something in uclamp_eff_get() too. Thanks -- Qais Yousef > > Only lightly tested: > > ---8<--- > > From: Dietmar Eggemann <dietmar.eggemann@xxxxxxx> > Date: Sun, 19 Apr 2020 01:20:17 +0200 > Subject: [PATCH] sched/core: uclamp: Move uclamp_rt_sync_default_util_min() > into uclamp_tg_restrict() > > Signed-off-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx> > --- > kernel/sched/core.c | 34 +++++++++++++++------------------- > 1 file changed, 15 insertions(+), 19 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 8f4e0d5c7daf..6802113d6d4b 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -899,12 +899,22 @@ unsigned int uclamp_rq_max_value(struct rq *rq, enum uclamp_id clamp_id, > } > > static inline struct uclamp_se > -uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id) > +uclamp_restrict(struct task_struct *p, enum uclamp_id clamp_id) > { > - struct uclamp_se uc_req = p->uclamp_req[clamp_id]; > -#ifdef CONFIG_UCLAMP_TASK_GROUP > - struct uclamp_se uc_max; > + struct uclamp_se uc_req, __maybe_unused uc_max; > + > + if (unlikely(rt_task(p)) && clamp_id == UCLAMP_MIN && > + !uc_req.user_defined) { > + struct uclamp_se *uc_se = &p->uclamp_req[UCLAMP_MIN]; > + int rt_min = sysctl_sched_rt_default_uclamp_util_min; > + > + if (uc_se->value != rt_min) > + uclamp_se_set(uc_se, rt_min, false); > + } > > + uc_req = p->uclamp_req[clamp_id]; > + > +#ifdef CONFIG_UCLAMP_TASK_GROUP > /* > * Tasks in autogroups or root task group will be > * restricted by system defaults. > @@ -933,7 +943,7 @@ uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id) > static inline struct uclamp_se > uclamp_eff_get(struct task_struct *p, enum uclamp_id clamp_id) > { > - struct uclamp_se uc_req = uclamp_tg_restrict(p, clamp_id); > + struct uclamp_se uc_req = uclamp_restrict(p, clamp_id); > struct uclamp_se uc_max = uclamp_default[clamp_id]; > > /* System default restrictions always apply */ > @@ -943,14 +953,6 @@ uclamp_eff_get(struct task_struct *p, enum uclamp_id clamp_id) > return uc_req; > } > > -static void uclamp_rt_sync_default_util_min(struct task_struct *p) > -{ > - struct uclamp_se *uc_se = &p->uclamp_req[UCLAMP_MIN]; > - > - if (!uc_se->user_defined) > - uclamp_se_set(uc_se, sysctl_sched_rt_default_uclamp_util_min, false); > -} > - > unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id) > { > struct uclamp_se uc_eff; > @@ -1057,12 +1059,6 @@ static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) > if (unlikely(!p->sched_class->uclamp_enabled)) > return; > > - /* > - * When sysctl_sched_rt_default_uclamp_util_min value is changed by the > - * user, we apply any new value on the next wakeup, which is here. > - */ > - uclamp_rt_sync_default_util_min(p); > - > for_each_clamp_id(clamp_id) > uclamp_rq_inc_id(rq, p, clamp_id); > > -- > 2.17.1