| From | Vincent Guittot <> | Date | Fri, 30 May 2014 21:24:48 +0200 | Subject | Re: [PATCH v2 10/11] sched: move cfs task on a CPU with higher capacity |
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On 30 May 2014 15:26, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote: > On 23/05/14 16:53, Vincent Guittot wrote: >> If the CPU is used for handling lot of IRQs, trig a load balance to check if >> it's worth moving its tasks on another CPU that has more capacity >> >> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> >> --- >> kernel/sched/fair.c | 13 +++++++++++++ >> 1 file changed, 13 insertions(+) >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index e8a30f9..2501e49 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -5948,6 +5948,13 @@ static bool update_sd_pick_busiest(struct lb_env *env, >> if (sgs->sum_nr_running > sgs->group_capacity) >> return true; >> >> + /* >> + * The group capacity is reduced probably because of activity from other > > Here 'group capacity' refers to sgs->group_power and not to > sgs->group_capacity, right?
yes, you're right it's cpu_power, i will correct the comment
> >> + * sched class or interrupts which use part of the available capacity >> + */ > > ... 'interrupts' only w/ CONFIG_IRQ_TIME_ACCOUNTING=y, right ?
yes, we need CONFIG_IRQ_TIME_ACCOUNTING in order to scale the cpu_power with time spent under irq. I have made test with and without this config to show impact (in the cover letter)
Thanks Vincent
> >> + if ((sg->sgp->power_orig * 100) > (sgs->group_power * env->sd->imbalance_pct)) >> + return true; >> + > [...] > > > -- > 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/
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