From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Rik van Riel <riel@surriel.com>, linux-kernel@vger.kernel.org
Cc: kernel-team@fb.com, pjt@google.com, peterz@infradead.org,
mingo@redhat.com, morten.rasmussen@arm.com, tglx@linutronix.de,
mgorman@techsingularity.net, vincent.guittot@linaro.org
Subject: Re: [PATCH 13/15] sched,fair: propagate sum_exec_runtime up the hierarchy
Date: Wed, 28 Aug 2019 09:51:36 +0200 [thread overview]
Message-ID: <f940abf6-3020-014c-74d7-d9be334e201c@arm.com> (raw)
In-Reply-To: <20190822021740.15554-14-riel@surriel.com>
On 22/08/2019 04:17, Rik van Riel wrote:
> Now that enqueue_task_fair and dequeue_task_fair no longer iterate up
> the hierarchy all the time, a method to lazily propagate sum_exec_runtime
> up the hierarchy is necessary.
>
> Once a tick, propagate the newly accumulated exec_runtime up the hierarchy,
> and feed it into CFS bandwidth control.
>
> Remove the pointless call to account_cfs_rq_runtime from update_curr,
> which is always called with a root cfs_rq.
But what about the call to account_cfs_rq_runtime() in
set_curr_task_fair()? Here you always call it with the root cfs_rq.
Shouldn't this be called also in a loop over all se's until !se->parent
(like in propagate_exec_runtime() further below).
> Signed-off-by: Rik van Riel <riel@surriel.com>
> ---
> include/linux/sched.h | 1 +
> kernel/sched/core.c | 1 +
> kernel/sched/fair.c | 22 ++++++++++++++++++++--
> 3 files changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 901c710363e7..bdca15b3afe7 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -454,6 +454,7 @@ struct sched_entity {
> int depth;
> unsigned long enqueued_h_load;
> unsigned long enqueued_h_weight;
> + u64 propagated_exec_runtime;
> struct load_weight h_load;
> struct sched_entity *parent;
> /* rq on which this entity is (to be) queued: */
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index fbd96900f715..9915d20e84a9 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -2137,6 +2137,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
> INIT_LIST_HEAD(&p->se.group_node);
>
> #ifdef CONFIG_FAIR_GROUP_SCHED
> + p->se.propagated_exec_runtime = 0;
> p->se.cfs_rq = NULL;
> #endif
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 5cfa3dbeba49..d6c881c5c4d5 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -898,8 +898,6 @@ static void update_curr(struct cfs_rq *cfs_rq)
> trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
> cgroup_account_cputime(curtask, delta_exec);
> account_group_exec_runtime(curtask, delta_exec);
> -
> - account_cfs_rq_runtime(cfs_rq, delta_exec);
> }
>
> static void update_curr_fair(struct rq *rq)
> @@ -3412,6 +3410,20 @@ static inline bool skip_blocked_update(struct sched_entity *se)
> return true;
> }
>
> +static void propagate_exec_runtime(struct cfs_rq *cfs_rq,
> + struct sched_entity *se)
> +{
> + struct sched_entity *parent = se->parent;
> + u64 diff = se->sum_exec_runtime - se->propagated_exec_runtime;
> +
> + if (parent) {
> + parent->sum_exec_runtime += diff;
> + account_cfs_rq_runtime(cfs_rq, diff);
> + }
> +
> + se->propagated_exec_runtime = se->sum_exec_runtime;
> +}
> +
> #else /* CONFIG_FAIR_GROUP_SCHED */
>
> static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) {}
> @@ -3423,6 +3435,11 @@ static inline int propagate_entity_load_avg(struct sched_entity *se)
>
> static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum) {}
>
> +static void propagate_exec_runtime(struct cfs_rq *cfs_rq,
> + struct sched_entity *se);
> +{
> +}
> +
> #endif /* CONFIG_FAIR_GROUP_SCHED */
>
> /**
> @@ -10157,6 +10174,7 @@ static void propagate_entity_cfs_rq(struct sched_entity *se, int flags)
> if (!(flags & DO_ATTACH))
> break;
>
> + propagate_exec_runtime(cfs_rq, se);
> update_cfs_group(se);
> }
> }
>
next prev parent reply other threads:[~2019-08-28 7:51 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-22 2:17 [PATCH RFC v4 0/15] sched,fair: flatten CPU controller runqueues Rik van Riel
2019-08-22 2:17 ` [PATCH 01/15] sched: introduce task_se_h_load helper Rik van Riel
2019-08-23 18:13 ` Dietmar Eggemann
2019-08-24 0:05 ` Rik van Riel
2019-08-22 2:17 ` [PATCH 02/15] sched: change /proc/sched_debug fields Rik van Riel
2019-08-22 2:17 ` [PATCH 03/15] sched,fair: redefine runnable_load_avg as the sum of task_h_load Rik van Riel
2019-08-28 13:50 ` Vincent Guittot
2019-08-28 14:47 ` Rik van Riel
2019-08-28 15:02 ` Vincent Guittot
2019-08-22 2:17 ` [PATCH 04/15] sched,fair: move runnable_load_avg to cfs_rq Rik van Riel
2019-08-22 2:17 ` [PATCH 05/15] sched,fair: remove cfs_rqs from leaf_cfs_rq_list bottom up Rik van Riel
2019-08-28 14:09 ` Vincent Guittot
2019-08-22 2:17 ` [PATCH 06/15] sched,cfs: use explicit cfs_rq of parent se helper Rik van Riel
2019-08-28 13:53 ` Vincent Guittot
2019-08-28 15:28 ` Rik van Riel
2019-08-28 16:34 ` Vincent Guittot
2019-08-22 2:17 ` [PATCH 07/15] sched,cfs: fix zero length timeslice calculation Rik van Riel
2019-08-28 16:59 ` Vincent Guittot
2019-08-22 2:17 ` [PATCH 08/15] sched,fair: simplify timeslice length code Rik van Riel
2019-08-28 17:32 ` Vincent Guittot
2019-08-28 23:18 ` Rik van Riel
2019-08-29 14:02 ` Vincent Guittot
2019-08-29 16:00 ` Rik van Riel
2019-08-30 6:41 ` Vincent Guittot
2019-08-30 15:01 ` Rik van Riel
2019-09-02 7:51 ` Vincent Guittot
2019-09-02 17:47 ` Rik van Riel
2019-08-22 2:17 ` [PATCH 09/15] sched,fair: refactor enqueue/dequeue_entity Rik van Riel
2019-09-03 15:38 ` Vincent Guittot
2019-09-03 20:27 ` Rik van Riel
2019-09-04 6:44 ` Vincent Guittot
2019-08-22 2:17 ` [PATCH 10/15] sched,fair: add helper functions for flattened runqueue Rik van Riel
2019-08-22 2:17 ` [PATCH 11/15] sched,fair: flatten hierarchical runqueues Rik van Riel
2019-08-23 18:14 ` Dietmar Eggemann
2019-08-24 1:16 ` Rik van Riel
2019-08-22 2:17 ` [PATCH 12/15] sched,fair: flatten update_curr functionality Rik van Riel
2019-08-27 10:37 ` Dietmar Eggemann
2019-08-22 2:17 ` [PATCH 13/15] sched,fair: propagate sum_exec_runtime up the hierarchy Rik van Riel
2019-08-28 7:51 ` Dietmar Eggemann [this message]
2019-08-28 13:14 ` Rik van Riel
2019-08-29 17:20 ` Dietmar Eggemann
2019-08-29 18:06 ` Rik van Riel
2019-08-22 2:17 ` [PATCH 14/15] sched,fair: ramp up task_se_h_weight quickly Rik van Riel
2019-08-22 2:17 ` [PATCH 15/15] sched,fair: scale vdiff in wakeup_preempt_entity Rik van Riel
2019-09-02 10:53 ` [PATCH RFC v4 0/15] sched,fair: flatten CPU controller runqueues Dietmar Eggemann
2019-09-03 1:44 ` Rik van Riel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=f940abf6-3020-014c-74d7-d9be334e201c@arm.com \
--to=dietmar.eggemann@arm.com \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mingo@redhat.com \
--cc=morten.rasmussen@arm.com \
--cc=peterz@infradead.org \
--cc=pjt@google.com \
--cc=riel@surriel.com \
--cc=tglx@linutronix.de \
--cc=vincent.guittot@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).