Messages in this thread | | | From | Xuewen Yan <> | Date | Wed, 20 Jul 2022 15:39:20 +0800 | Subject | Re: [PATCH 7/7] sched/uclamp: Cater for uclamp in find_energy_efficient_cpu()'s early exit condition |
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Hi Qais
On Thu, Jun 30, 2022 at 3:48 AM Qais Yousef <qais.yousef@arm.com> wrote: > > If the utilization of the woken up task is 0, we skip the energy > calculation because it has no impact. > > But if the task is boosted (uclamp_min != 0) will have an impact on task > placement and frequency selection. Only skip if the util is truly > 0 after applying uclamp values. > > Change uclamp_task_cpu() signature to avoid unnecessary additional calls > to uclamp_eff_get(). feec() is the only user now. > > Fixes: 732cd75b8c920 ("sched/fair: Select an energy-efficient CPU on task wake-up") > Signed-off-by: Qais Yousef <qais.yousef@arm.com> > --- > kernel/sched/fair.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 499ef7a7288c..a112ca45864c 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -4057,14 +4057,16 @@ static inline unsigned long task_util_est(struct task_struct *p) > } > > #ifdef CONFIG_UCLAMP_TASK > -static inline unsigned long uclamp_task_util(struct task_struct *p) > +static inline unsigned long uclamp_task_util(struct task_struct *p, > + unsigned long uclamp_min, > + unsigned long uclamp_max) > { > - return clamp(task_util_est(p), > - uclamp_eff_value(p, UCLAMP_MIN), > - uclamp_eff_value(p, UCLAMP_MAX)); > + return clamp(task_util_est(p), uclamp_min, uclamp_max); > } > #else > -static inline unsigned long uclamp_task_util(struct task_struct *p) > +static inline unsigned long uclamp_task_util(struct task_struct *p, > + unsigned long uclamp_min, > + unsigned long uclamp_max) > { > return task_util_est(p); > } > @@ -6913,7 +6915,7 @@ static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) > target = prev_cpu; > > sync_entity_load_avg(&p->se); > - if (!task_util_est(p)) > + if (!uclamp_task_util(p, p_util_min, p_util_max))
Is it not enough to just replace the task_util_est with the uclamp_task_util? If change the definition of uclamp_task_util, that means it have to get task's uclamp first if user want to call the function, may increase the code complex farther more?
> goto unlock; > > for (; pd; pd = pd->next) { > -- > 2.25.1 >
BR --- xuewen.yan
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