Messages in this thread | | | Date | Mon, 1 Jul 2013 16:49:22 +0800 | Subject | Re: [PATCH 0/2] sched: add trace event for per-entity tracking | From | Lei Wen <> |
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Alex,
On Mon, Jul 1, 2013 at 4:06 PM, Alex Shi <alex.shi@intel.com> wrote: > On 07/01/2013 03:10 PM, Lei Wen wrote: >> Thanks for the per-entity tracking feature, we could know the details of >> each task by its help. >> This patch add its trace support, so that we could quickly know the system >> status in a large time scale, like now we may get each runqueue's usage ratio by: >> >> cfs_rq's usage ratio = cfs_rq->runnable_load_avg/cfs_rq->load.weight >> > > the direct usage ratio is rq.avg.runnable_avg_sum / rq.avg.runnable_avg_period.
From the parsed data diagram, seem more pretty than my previous use load as the calculation one. :) BTW, do you think there is some meaning for doing below calculation? cfs_rq->runnable_load_avg/cfs_rq->load.weight
I think by this calculation from the runnable_avg_load/blocked_avg_load trace result, we may catch some abnormal load distribution when debugging.
> > one patch from obsolete power-scheduling could be reference for this: > git@github.com:alexshi/power-scheduling.git power-scheduling > > From 081cd4bcbccfaa1930b031e4dfbf9d23b8c0d5ab Mon Sep 17 00:00:00 2001 > From: Alex Shi <alex.shi@intel.com> > Date: Fri, 7 Dec 2012 21:37:58 +0800 > Subject: [PATCH 02/23] sched: log the cpu utilization at rq > > The cpu's utilization is to measure how busy is the cpu. > util = cpu_rq(cpu)->avg.runnable_avg_sum * SCHED_POEWR_SCALE > / cpu_rq(cpu)->avg.runnable_avg_period; > > Since the util is no more than 1, we scale its value with 1024, same as > SCHED_POWER_SCALE and set the FULL_UTIL as 1024. > > In later power aware scheduling, we are sensitive for how busy of the > cpu. Since as to power consuming, it is tight related with cpu busy > time. > > BTW, rq->util can be used for any purposes if needed, not only power > scheduling. > > Signed-off-by: Alex Shi <alex.shi@intel.com>
Nice patch, would it be merged? :)
Thanks, Lei > --- > include/linux/sched.h | 2 +- > kernel/sched/debug.c | 1 + > kernel/sched/fair.c | 5 +++++ > kernel/sched/sched.h | 4 ++++ > 4 files changed, 11 insertions(+), 1 deletion(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 9539597..4e4d9ee 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -794,7 +794,7 @@ enum cpu_idle_type { > #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT) > > /* > - * Increase resolution of cpu_power calculations > + * Increase resolution of cpu_power and rq->util calculations > */ > #define SCHED_POWER_SHIFT 10 > #define SCHED_POWER_SCALE (1L << SCHED_POWER_SHIFT) > diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c > index 75024a6..f5db759 100644 > --- a/kernel/sched/debug.c > +++ b/kernel/sched/debug.c > @@ -311,6 +311,7 @@ do { \ > > P(ttwu_count); > P(ttwu_local); > + P(util); > > #undef P > #undef P64 > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 2e49c3f..7124244 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -1495,8 +1495,13 @@ static void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq, int force_update) > > static inline void update_rq_runnable_avg(struct rq *rq, int runnable) > { > + u32 period; > __update_entity_runnable_avg(rq->clock_task, &rq->avg, runnable); > __update_tg_runnable_avg(&rq->avg, &rq->cfs); > + > + period = rq->avg.runnable_avg_period ? rq->avg.runnable_avg_period : 1; > + rq->util = (u64)(rq->avg.runnable_avg_sum << SCHED_POWER_SHIFT) > + / period; > } > > /* Add the load generated by se into cfs_rq's child load-average */ > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > index 804ee41..8682110 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -351,6 +351,9 @@ extern struct root_domain def_root_domain; > > #endif /* CONFIG_SMP */ > > +/* full cpu utilization */ > +#define FULL_UTIL SCHED_POWER_SCALE > + > /* > * This is the main, per-CPU runqueue data structure. > * > @@ -482,6 +485,7 @@ struct rq { > #endif > > struct sched_avg avg; > + unsigned int util; > }; > > static inline int cpu_of(struct rq *rq) > -- > 1.7.12 > > -- > Thanks > Alex > -- > 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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