Commit-ID: 9d20ad7dfc9a5cc64e33d725902d3863d350a66a Gitweb: https://git.kernel.org/tip/9d20ad7dfc9a5cc64e33d725902d3863d350a66a Author: Patrick Bellasi <patrick.bell...@arm.com> AuthorDate: Fri, 21 Jun 2019 09:42:11 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 24 Jun 2019 19:23:48 +0200
sched/uclamp: Add uclamp_util_with() So far uclamp_util() allows to clamp a specified utilization considering the clamp values requested by RUNNABLE tasks in a CPU. For the Energy Aware Scheduler (EAS) it is interesting to test how clamp values will change when a task is becoming RUNNABLE on a given CPU. For example, EAS is interested in comparing the energy impact of different scheduling decisions and the clamp values can play a role on that. Add uclamp_util_with() which allows to clamp a given utilization by considering the possible impact on CPU clamp values of a specified task. Signed-off-by: Patrick Bellasi <patrick.bell...@arm.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Alessio Balsini <bals...@android.com> Cc: Dietmar Eggemann <dietmar.eggem...@arm.com> Cc: Joel Fernandes <joe...@google.com> Cc: Juri Lelli <juri.le...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmus...@arm.com> Cc: Paul Turner <p...@google.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Quentin Perret <quentin.per...@arm.com> Cc: Rafael J . Wysocki <rafael.j.wyso...@intel.com> Cc: Steve Muckle <smuc...@google.com> Cc: Suren Baghdasaryan <sur...@google.com> Cc: Tejun Heo <t...@kernel.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Todd Kjos <tk...@google.com> Cc: Vincent Guittot <vincent.guit...@linaro.org> Cc: Viresh Kumar <viresh.ku...@linaro.org> Link: https://lkml.kernel.org/r/20190621084217.8167-11-patrick.bell...@arm.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/core.c | 13 +++++++++++++ kernel/sched/sched.h | 21 ++++++++++++++++++++- 2 files changed, 33 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6cd5133f0c2a..fa43ce3962e7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -880,6 +880,19 @@ uclamp_eff_get(struct task_struct *p, unsigned int clamp_id) return uc_req; } +unsigned int uclamp_eff_value(struct task_struct *p, unsigned int clamp_id) +{ + struct uclamp_se uc_eff; + + /* Task currently refcounted: use back-annotated (effective) value */ + if (p->uclamp[clamp_id].active) + return p->uclamp[clamp_id].value; + + uc_eff = uclamp_eff_get(p, clamp_id); + + return uc_eff.value; +} + /* * When a task is enqueued on a rq, the clamp bucket currently defined by the * task's uclamp::bucket_id is refcounted on that rq. This also immediately diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 9b0c77a99346..1783f6b4c2e0 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2266,11 +2266,20 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} #endif /* CONFIG_CPU_FREQ */ #ifdef CONFIG_UCLAMP_TASK -static inline unsigned int uclamp_util(struct rq *rq, unsigned int util) +unsigned int uclamp_eff_value(struct task_struct *p, unsigned int clamp_id); + +static __always_inline +unsigned int uclamp_util_with(struct rq *rq, unsigned int util, + struct task_struct *p) { unsigned int min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value); unsigned int max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); + if (p) { + min_util = max(min_util, uclamp_eff_value(p, UCLAMP_MIN)); + max_util = max(max_util, uclamp_eff_value(p, UCLAMP_MAX)); + } + /* * Since CPU's {min,max}_util clamps are MAX aggregated considering * RUNNABLE tasks with _different_ clamps, we can end up with an @@ -2281,7 +2290,17 @@ static inline unsigned int uclamp_util(struct rq *rq, unsigned int util) return clamp(util, min_util, max_util); } + +static inline unsigned int uclamp_util(struct rq *rq, unsigned int util) +{ + return uclamp_util_with(rq, util, NULL); +} #else /* CONFIG_UCLAMP_TASK */ +static inline unsigned int uclamp_util_with(struct rq *rq, unsigned int util, + struct task_struct *p) +{ + return util; +} static inline unsigned int uclamp_util(struct rq *rq, unsigned int util) { return util;
