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Groups > linux.kernel > #1339658
| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks |
| Date | 2016-02-22 16:40 +0100 |
| Message-ID | <r50KC-7Jl-9@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <r3Oit-24t-5@gated-at.bofh.it> <r3WpI-7Yk-19@gated-at.bofh.it> <r3X2q-8uR-15@gated-at.bofh.it> <r4WnD-4v7-13@gated-at.bofh.it> <r4ZOy-77E-19@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Feb 22, 2016 at 03:33:02PM +0100, Vincent Guittot wrote:
> > Right, so I had a wee look at that again, and had a quick chat with Juri
> > on IRC. So the main difference seems to be that you guys want to know
> > why the utilization changed, as opposed to purely _that_ it changed.
>
> Yes, the main goal was to be able to filter the useful and useless
> update of rq's utilization in order to minimize/optimize the trig of
> an update of the frequency. These patches have been made for a cpufreq
> driver that reacts far slower than scheduler. It's might worth
> starting with a simple solution and update it after
Right, always start simple :-)
> > And hence you have callbacks all over the place.
> >
> > I'm not too sure I really like that too much, it bloats the code and
> > somewhat obfuscates the point.
> >
> > So I would really like there to be just the one callback when we
> > actually compute a new number, and that is update_load_avg().
> >
> > Now I think we can 'easily' propagate the information you want into
> > update_load_avg() (see below), but I would like to see actual arguments
> > for why you would need this.
>
> Your proposal is interesting except that we are interested in the rq's
> utilization more that se's ones so we should better use
> update_cfs_rq_load_avg and few additional place like
> attach_entity_load_avg which bypasses update_cfs_rq_load_avg to update
> rq's utilization and load
Ah, so the intent was to use the rq->cfs util, but I might have gotten
a little lost in the load update code (I always get confused by that
code if I haven't looked at it for a while).
We can put the hook in update_cfs_rq_load_avg(), that shouldn't be a
problem.
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2859,29 +2859,6 @@ static inline int update_cfs_rq_load_avg
cfs_rq->load_last_update_time_copy = sa->last_update_time;
#endif
- return decayed || removed;
-}
-
-/* Update task and its cfs_rq load average */
-static inline void update_load_avg(struct sched_entity *se, int update_tg,
- enum load_update_type type)
-{
- struct cfs_rq *cfs_rq = cfs_rq_of(se);
- u64 now = cfs_rq_clock_task(cfs_rq);
- struct rq *rq = rq_of(cfs_rq);
- int cpu = cpu_of(rq);
-
- /*
- * Track task load average for carrying it to new CPU after migrated, and
- * track group sched_entity load average for task_h_load calc in migration
- */
- __update_load_avg(now, cpu, &se->avg,
- se->on_rq * scale_load_down(se->load.weight),
- cfs_rq->curr == se, NULL);
-
- if (update_cfs_rq_load_avg(now, cfs_rq) && update_tg)
- update_tg_load_avg(cfs_rq, 0);
-
if (cpu == smp_processor_id() && &rq->cfs == cfs_rq) {
unsigned long max = rq->cpu_capacity_orig;
@@ -2904,6 +2881,29 @@ static inline void update_load_avg(struc
cpufreq_update_util(rq_clock(rq),
min(cfs_rq->avg.util_avg, max), max);
}
+
+ return decayed || removed;
+}
+
+/* Update task and its cfs_rq load average */
+static inline void update_load_avg(struct sched_entity *se, int update_tg,
+ enum load_update_type type)
+{
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+ u64 now = cfs_rq_clock_task(cfs_rq);
+ struct rq *rq = rq_of(cfs_rq);
+ int cpu = cpu_of(rq);
+
+ /*
+ * Track task load average for carrying it to new CPU after migrated, and
+ * track group sched_entity load average for task_h_load calc in migration
+ */
+ __update_load_avg(now, cpu, &se->avg,
+ se->on_rq * scale_load_down(se->load.weight),
+ cfs_rq->curr == se, NULL);
+
+ if (update_cfs_rq_load_avg(now, cfs_rq) && update_tg)
+ update_tg_load_avg(cfs_rq, 0);
}
static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v6 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-10 16:40 +0100
[PATCH v7 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-11 00:10 +0100
[PATCH v8 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-11 18:30 +0100
[PATCH v9 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-12 14:20 +0100
[PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-15 22:50 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rafael@kernel.org> - 2016-02-18 21:30 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Juri Lelli <juri.lelli@arm.com> - 2016-02-19 09:10 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> - 2016-02-19 17:50 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Steve Muckle <steve.muckle@linaro.org> - 2016-02-19 18:30 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-19 23:40 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Steve Muckle <steve.muckle@linaro.org> - 2016-02-23 05:00 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Peter Zijlstra <peterz@infradead.org> - 2016-02-22 12:00 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Vincent Guittot <vincent.guittot@linaro.org> - 2016-02-22 15:40 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Peter Zijlstra <peterz@infradead.org> - 2016-02-22 16:40 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Juri Lelli <juri.lelli@arm.com> - 2016-02-22 15:40 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Peter Zijlstra <peterz@infradead.org> - 2016-02-22 16:50 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rafael@kernel.org> - 2016-02-22 22:50 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Juri Lelli <juri.lelli@arm.com> - 2016-02-19 18:30 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-19 23:30 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Juri Lelli <juri.lelli@arm.com> - 2016-02-22 10:50 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rafael@kernel.org> - 2016-02-22 22:50 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Juri Lelli <juri.lelli@arm.com> - 2016-02-23 12:10 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-24 03:00 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-22 11:50 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-19 23:20 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Juri Lelli <juri.lelli@arm.com> - 2016-02-22 10:40 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rafael@kernel.org> - 2016-02-22 22:30 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks Juri Lelli <juri.lelli@arm.com> - 2016-02-23 12:10 +0100
Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-24 03:00 +0100
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