From: Aaron Lu <aaron.lu@linux.alibaba.com>
To: Vineeth Remanan Pillai <vpillai@digitalocean.com>
Cc: "Tim Chen" <tim.c.chen@linux.intel.com>,
"Julien Desfossez" <jdesfossez@digitalocean.com>,
"Dario Faggioli" <dfaggioli@suse.com>,
"Li, Aubrey" <aubrey.li@linux.intel.com>,
"Aubrey Li" <aubrey.intel@gmail.com>,
"Nishanth Aravamudan" <naravamudan@digitalocean.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Ingo Molnar" <mingo@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Paul Turner" <pjt@google.com>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Linux List Kernel Mailing" <linux-kernel@vger.kernel.org>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
"Kees Cook" <keescook@chromium.org>,
"Greg Kerr" <kerrnel@google.com>, "Phil Auld" <pauld@redhat.com>,
"Valentin Schneider" <valentin.schneider@arm.com>,
"Mel Gorman" <mgorman@techsingularity.net>,
"Pawan Gupta" <pawan.kumar.gupta@linux.intel.com>,
"Paolo Bonzini" <pbonzini@redhat.com>
Subject: Re: [RFC PATCH v3 00/16] Core scheduling v3
Date: Mon, 14 Oct 2019 17:57:25 +0800 [thread overview]
Message-ID: <20191014095725.GA78693@aaronlu> (raw)
In-Reply-To: <CANaguZBevMsQ_Zy1ozKn2Z5Uj6WBviC6UU+zpTQOVdDDLK6r2w@mail.gmail.com>
On Sun, Oct 13, 2019 at 08:44:32AM -0400, Vineeth Remanan Pillai wrote:
> On Fri, Oct 11, 2019 at 11:55 PM Aaron Lu <aaron.lu@linux.alibaba.com> wrote:
>
> >
> > I don't think we need do the normalization afterwrads and it appears
> > we are on the same page regarding core wide vruntime.
Should be "we are not on the same page..."
[...]
> > The weird thing about my patch is, the min_vruntime is often increased,
> > it doesn't point to the smallest value as in a traditional cfs_rq. This
> > probabaly can be changed to follow the tradition, I don't quite remember
> > why I did this, will need to check this some time later.
>
> Yeah, I noticed this. In my patch, I had already accounted for this and changed
> to min() instead of max() which is more logical that min_vruntime should be the
> minimum of both the run queue.
I now remembered why I used max().
Assume rq1 and rq2's min_vruntime are both at 2000 and the core wide
min_vruntime is also 2000. Also assume both runqueues are empty at the
moment. Then task t1 is queued to rq1 and runs for a long time while rq2
keeps empty. rq1's min_vruntime will be incremented all the time while
the core wide min_vruntime stays at 2000 if min() is used. Then when
another task gets queued to rq2, it will get really large unfair boost
by using a much smaller min_vruntime as its base.
To fix this, either max() is used as is done in my patch, or adjust
rq2's min_vruntime to be the same as rq1's on each
update_core_cfs_min_vruntime() when rq2 is found empty and then use
min() to get the core wide min_vruntime. Looks not worth the trouble to
use min().
next prev parent reply other threads:[~2019-10-14 9:57 UTC|newest]
Thread overview: 161+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-29 20:36 [RFC PATCH v3 00/16] Core scheduling v3 Vineeth Remanan Pillai
2019-05-29 20:36 ` [RFC PATCH v3 01/16] stop_machine: Fix stop_cpus_in_progress ordering Vineeth Remanan Pillai
2019-08-08 10:54 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2019-08-26 16:19 ` [RFC PATCH v3 01/16] " mark gross
2019-08-26 16:59 ` Peter Zijlstra
2019-05-29 20:36 ` [RFC PATCH v3 02/16] sched: Fix kerneldoc comment for ia64_set_curr_task Vineeth Remanan Pillai
2019-08-08 10:55 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2019-08-26 16:20 ` [RFC PATCH v3 02/16] " mark gross
2019-05-29 20:36 ` [RFC PATCH v3 03/16] sched: Wrap rq::lock access Vineeth Remanan Pillai
2019-05-29 20:36 ` [RFC PATCH v3 04/16] sched/{rt,deadline}: Fix set_next_task vs pick_next_task Vineeth Remanan Pillai
2019-08-08 10:55 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2019-05-29 20:36 ` [RFC PATCH v3 05/16] sched: Add task_struct pointer to sched_class::set_curr_task Vineeth Remanan Pillai
2019-08-08 10:57 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2019-05-29 20:36 ` [RFC PATCH v3 06/16] sched/fair: Export newidle_balance() Vineeth Remanan Pillai
2019-08-08 10:58 ` [tip:sched/core] sched/fair: Expose newidle_balance() tip-bot for Peter Zijlstra
2019-05-29 20:36 ` [RFC PATCH v3 07/16] sched: Allow put_prev_task() to drop rq->lock Vineeth Remanan Pillai
2019-08-08 10:58 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2019-08-26 16:51 ` [RFC PATCH v3 07/16] " mark gross
2019-05-29 20:36 ` [RFC PATCH v3 08/16] sched: Rework pick_next_task() slow-path Vineeth Remanan Pillai
2019-08-08 10:59 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2019-08-26 17:01 ` [RFC PATCH v3 08/16] " mark gross
2019-05-29 20:36 ` [RFC PATCH v3 09/16] sched: Introduce sched_class::pick_task() Vineeth Remanan Pillai
2019-08-26 17:14 ` mark gross
2019-05-29 20:36 ` [RFC PATCH v3 10/16] sched: Core-wide rq->lock Vineeth Remanan Pillai
2019-05-31 11:08 ` Peter Zijlstra
2019-05-31 15:23 ` Vineeth Pillai
2019-05-29 20:36 ` [RFC PATCH v3 11/16] sched: Basic tracking of matching tasks Vineeth Remanan Pillai
2019-08-26 20:59 ` mark gross
2019-05-29 20:36 ` [RFC PATCH v3 12/16] sched: A quick and dirty cgroup tagging interface Vineeth Remanan Pillai
2019-05-29 20:36 ` [RFC PATCH v3 13/16] sched: Add core wide task selection and scheduling Vineeth Remanan Pillai
2019-06-07 23:36 ` Pawan Gupta
2019-05-29 20:36 ` [RFC PATCH v3 14/16] sched/fair: Add a few assertions Vineeth Remanan Pillai
2019-05-29 20:36 ` [RFC PATCH v3 15/16] sched: Trivial forced-newidle balancer Vineeth Remanan Pillai
2019-05-29 20:36 ` [RFC PATCH v3 16/16] sched: Debug bits Vineeth Remanan Pillai
2019-05-29 21:02 ` Peter Oskolkov
2019-05-30 14:04 ` [RFC PATCH v3 00/16] Core scheduling v3 Aubrey Li
2019-05-30 14:17 ` Julien Desfossez
2019-05-31 4:55 ` Aubrey Li
2019-05-31 3:01 ` Aaron Lu
2019-05-31 5:12 ` Aubrey Li
2019-05-31 6:09 ` Aaron Lu
2019-05-31 6:53 ` Aubrey Li
2019-05-31 7:44 ` Aaron Lu
2019-05-31 8:26 ` Aubrey Li
2019-05-31 21:08 ` Julien Desfossez
2019-06-06 15:26 ` Julien Desfossez
2019-06-12 1:52 ` Li, Aubrey
2019-06-12 16:06 ` Julien Desfossez
2019-06-12 16:33 ` Julien Desfossez
2019-06-13 0:03 ` Subhra Mazumdar
2019-06-13 3:22 ` Julien Desfossez
2019-06-17 2:51 ` Aubrey Li
2019-06-19 18:33 ` Julien Desfossez
2019-07-18 10:07 ` Aaron Lu
2019-07-18 23:27 ` Tim Chen
2019-07-19 5:52 ` Aaron Lu
2019-07-19 11:48 ` Aubrey Li
2019-07-19 18:33 ` Tim Chen
2019-07-22 10:26 ` Aubrey Li
2019-07-22 10:43 ` Aaron Lu
2019-07-23 2:52 ` Aubrey Li
2019-07-25 14:30 ` Aaron Lu
2019-07-25 14:31 ` [RFC PATCH 1/3] wrapper for cfs_rq->min_vruntime Aaron Lu
2019-07-25 14:32 ` [PATCH 2/3] core vruntime comparison Aaron Lu
2019-08-06 14:17 ` Peter Zijlstra
2019-07-25 14:33 ` [PATCH 3/3] temp hack to make tick based schedule happen Aaron Lu
2019-07-25 21:42 ` [RFC PATCH v3 00/16] Core scheduling v3 Li, Aubrey
2019-07-26 15:21 ` Julien Desfossez
2019-07-26 21:29 ` Tim Chen
2019-07-31 2:42 ` Li, Aubrey
2019-08-02 15:37 ` Julien Desfossez
2019-08-05 15:55 ` Tim Chen
2019-08-06 3:24 ` Aaron Lu
2019-08-06 6:56 ` Aubrey Li
2019-08-06 7:04 ` Aaron Lu
2019-08-06 12:24 ` Vineeth Remanan Pillai
2019-08-06 13:49 ` Aaron Lu
2019-08-06 16:14 ` Vineeth Remanan Pillai
2019-08-06 14:16 ` Peter Zijlstra
2019-08-06 15:53 ` Vineeth Remanan Pillai
2019-08-06 17:03 ` Tim Chen
2019-08-06 17:12 ` Peter Zijlstra
2019-08-06 21:19 ` Tim Chen
2019-08-08 6:47 ` Aaron Lu
2019-08-08 17:27 ` Tim Chen
2019-08-08 21:42 ` Tim Chen
2019-08-10 14:15 ` Aaron Lu
2019-08-12 15:38 ` Vineeth Remanan Pillai
2019-08-13 2:24 ` Aaron Lu
2019-08-08 12:55 ` Aaron Lu
2019-08-08 16:39 ` Tim Chen
2019-08-10 14:18 ` Aaron Lu
2019-08-05 20:09 ` Phil Auld
2019-08-06 13:54 ` Aaron Lu
2019-08-06 14:17 ` Phil Auld
2019-08-06 14:41 ` Aaron Lu
2019-08-06 14:55 ` Phil Auld
2019-08-07 8:58 ` Dario Faggioli
2019-08-07 17:10 ` Tim Chen
2019-08-15 16:09 ` Dario Faggioli
2019-08-16 2:33 ` Aaron Lu
2019-09-05 1:44 ` Julien Desfossez
2019-09-06 22:17 ` Tim Chen
2019-09-18 21:27 ` Tim Chen
2019-09-06 18:30 ` Tim Chen
2019-09-11 14:02 ` Aaron Lu
2019-09-11 16:19 ` Tim Chen
2019-09-11 16:47 ` Vineeth Remanan Pillai
2019-09-12 12:35 ` Aaron Lu
2019-09-12 17:29 ` Tim Chen
2019-09-13 14:15 ` Aaron Lu
2019-09-13 17:13 ` Tim Chen
2019-09-30 11:53 ` Vineeth Remanan Pillai
2019-10-02 20:48 ` Vineeth Remanan Pillai
2019-10-10 13:54 ` Aaron Lu
2019-10-10 14:29 ` Vineeth Remanan Pillai
2019-10-11 7:33 ` Aaron Lu
2019-10-11 11:32 ` Vineeth Remanan Pillai
2019-10-11 12:01 ` Aaron Lu
2019-10-11 12:10 ` Vineeth Remanan Pillai
2019-10-12 3:55 ` Aaron Lu
2019-10-13 12:44 ` Vineeth Remanan Pillai
2019-10-14 9:57 ` Aaron Lu [this message]
2019-10-21 12:30 ` Vineeth Remanan Pillai
2019-09-12 12:04 ` Aaron Lu
2019-09-12 17:05 ` Tim Chen
2019-09-13 13:57 ` Aaron Lu
2019-09-12 23:12 ` Aubrey Li
2019-09-15 14:14 ` Aaron Lu
2019-09-18 1:33 ` Aubrey Li
2019-09-18 20:40 ` Tim Chen
2019-09-18 22:16 ` Aubrey Li
2019-09-30 14:36 ` Vineeth Remanan Pillai
2019-10-29 20:40 ` Julien Desfossez
2019-11-01 21:42 ` Tim Chen
2019-10-29 9:11 ` Dario Faggioli
2019-10-29 9:15 ` Dario Faggioli
2019-10-29 9:16 ` Dario Faggioli
2019-10-29 9:17 ` Dario Faggioli
2019-10-29 9:18 ` Dario Faggioli
2019-10-29 9:18 ` Dario Faggioli
2019-10-29 9:19 ` Dario Faggioli
2019-10-29 9:20 ` Dario Faggioli
2019-10-29 20:34 ` Julien Desfossez
2019-11-15 16:30 ` Dario Faggioli
2019-09-25 2:40 ` Aubrey Li
2019-09-25 17:24 ` Tim Chen
2019-09-25 22:07 ` Aubrey Li
2019-09-30 15:22 ` Julien Desfossez
2019-08-27 21:14 ` Matthew Garrett
2019-08-27 21:50 ` Peter Zijlstra
2019-08-28 15:30 ` Phil Auld
2019-08-28 16:01 ` Peter Zijlstra
2019-08-28 16:37 ` Tim Chen
2019-08-29 14:30 ` Phil Auld
2019-08-29 14:38 ` Peter Zijlstra
2019-09-10 14:27 ` Julien Desfossez
2019-09-18 21:12 ` Tim Chen
2019-08-28 15:59 ` Tim Chen
2019-08-28 16:16 ` Peter Zijlstra
2019-08-27 23:24 ` Aubrey Li
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