From: Vincent Guittot <vincent.guittot@linaro.org>
To: Qais Yousef <qais.yousef@arm.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Phil Auld <pauld@redhat.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Quentin Perret <quentin.perret@arm.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Morten Rasmussen <Morten.Rasmussen@arm.com>,
Hillf Danton <hdanton@sina.com>, Parth Shah <parth@linux.ibm.com>,
Rik van Riel <riel@surriel.com>
Subject: Re: [PATCH v4 11/11] sched/fair: rework find_idlest_group
Date: Wed, 20 Nov 2019 14:21:56 +0100 [thread overview]
Message-ID: <CAKfTPtDh7HAv2Krx9cRKcA+Zy=erYkykyZZj4=nkRoTEdY=oFw@mail.gmail.com> (raw)
In-Reply-To: <20191120115844.scli3gprgd5vvlt4@e107158-lin.cambridge.arm.com>
Hi Qais,
On Wed, 20 Nov 2019 at 12:58, Qais Yousef <qais.yousef@arm.com> wrote:
>
> Hi Vincent
>
> On 10/18/19 15:26, Vincent Guittot wrote:
> > The slow wake up path computes per sched_group statisics to select the
> > idlest group, which is quite similar to what load_balance() is doing
> > for selecting busiest group. Rework find_idlest_group() to classify the
> > sched_group and select the idlest one following the same steps as
> > load_balance().
> >
> > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > ---
>
> LTP test has caught a regression in perf_event_open02 test on linux-next and I
> bisected it to this patch.
>
> That is checking out next-20191119 tag and reverting this patch on top the test
> passes. Without the revert the test fails.
>
> I think this patch disturbs this part of the test:
>
> https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/perf_event_open/perf_event_open02.c#L209
>
> When I revert this patch count_hardware_counters() returns a non zero value.
> But with it applied it returns 0 which indicates that the condition terminates
> earlier than what the test expects.
Thanks for the report and starting analysing it
>
> I'm failing to see the connection yet, but since I spent enough time bisecting
> it I thought I'll throw this out before I continue to bottom it out in hope it
> rings a bell for you or someone else.
I will try to reproduce the problem and understand why it's failing
because i don't have any clue of the relation between both for now
>
> The problem was consistently reproducible on Juno-r2.
>
> LTP was compiled from 20190930 tag using
>
> ./configure --host=aarch64-linux-gnu --prefix=~/arm64-ltp/
> make && make install
>
>
>
> *** Output of the test when it fails ***
>
> # ./perf_event_open02 -v
> at iteration:0 value:254410384 time_enabled:195570320 time_running:156044100
> perf_event_open02 0 TINFO : overall task clock: 166935520
> perf_event_open02 0 TINFO : hw sum: 1200812256, task clock sum: 667703360
> hw counters: 300202518 300202881 300203246 300203611
> task clock counters: 166927400 166926780 166925660 166923520
> perf_event_open02 0 TINFO : ratio: 3.999768
> perf_event_open02 0 TINFO : nhw: 0.000100 /* I added this extra line for debug */
> perf_event_open02 1 TFAIL : perf_event_open02.c:370: test failed (ratio was greater than )
>
>
>
> *** Output of the test when it passes (this patch reverted) ***
>
> # ./perf_event_open02 -v
> at iteration:0 value:300271482 time_enabled:177756080 time_running:177756080
> at iteration:1 value:300252655 time_enabled:166939100 time_running:166939100
> at iteration:2 value:300252877 time_enabled:166924920 time_running:166924920
> at iteration:3 value:300242545 time_enabled:166909620 time_running:166909620
> at iteration:4 value:300250779 time_enabled:166918540 time_running:166918540
> at iteration:5 value:300250660 time_enabled:166922180 time_running:166922180
> at iteration:6 value:258369655 time_enabled:167388920 time_running:143996600
> perf_event_open02 0 TINFO : overall task clock: 167540640
> perf_event_open02 0 TINFO : hw sum: 1801473873, task clock sum: 1005046160
> hw counters: 177971955 185132938 185488818 185488199 185480943 185477118 179657001 172499668 172137672 172139561
> task clock counters: 99299900 103293440 103503840 103502040 103499020 103496160 100224320 96227620 95999400 96000420
> perf_event_open02 0 TINFO : ratio: 5.998820
> perf_event_open02 0 TINFO : nhw: 6.000100 /* I added this extra line for debug */
> perf_event_open02 1 TPASS : test passed
>
> Thanks
>
> --
> Qais Yousef
next prev parent reply other threads:[~2019-11-20 13:22 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 13:26 [PATCH v4 00/10] sched/fair: rework the CFS load balance Vincent Guittot
2019-10-18 13:26 ` [PATCH v4 01/11] sched/fair: clean up asym packing Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Clean " tip-bot2 for Vincent Guittot
2019-10-30 14:51 ` [PATCH v4 01/11] sched/fair: clean " Mel Gorman
2019-10-30 16:03 ` Vincent Guittot
2019-10-18 13:26 ` [PATCH v4 02/11] sched/fair: rename sum_nr_running to sum_h_nr_running Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Rename sg_lb_stats::sum_nr_running " tip-bot2 for Vincent Guittot
2019-10-30 14:53 ` [PATCH v4 02/11] sched/fair: rename sum_nr_running " Mel Gorman
2019-10-18 13:26 ` [PATCH v4 03/11] sched/fair: remove meaningless imbalance calculation Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Remove " tip-bot2 for Vincent Guittot
2019-10-18 13:26 ` [PATCH v4 04/11] sched/fair: rework load_balance Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Rework load_balance() tip-bot2 for Vincent Guittot
2019-10-30 15:45 ` [PATCH v4 04/11] sched/fair: rework load_balance Mel Gorman
2019-10-30 16:16 ` Valentin Schneider
2019-10-31 9:09 ` Vincent Guittot
2019-10-31 10:15 ` Mel Gorman
2019-10-31 11:13 ` Vincent Guittot
2019-10-31 11:40 ` Mel Gorman
2019-11-08 16:35 ` Vincent Guittot
2019-11-08 18:37 ` Mel Gorman
2019-11-12 10:58 ` Vincent Guittot
2019-11-12 15:06 ` Mel Gorman
2019-11-12 15:40 ` Vincent Guittot
2019-11-12 17:45 ` Mel Gorman
2019-11-18 13:50 ` Ingo Molnar
2019-11-18 13:57 ` Vincent Guittot
2019-11-18 14:51 ` Mel Gorman
2019-10-18 13:26 ` [PATCH v4 05/11] sched/fair: use rq->nr_running when balancing load Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Use " tip-bot2 for Vincent Guittot
2019-10-30 15:54 ` [PATCH v4 05/11] sched/fair: use " Mel Gorman
2019-10-18 13:26 ` [PATCH v4 06/11] sched/fair: use load instead of runnable load in load_balance Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Use load instead of runnable load in load_balance() tip-bot2 for Vincent Guittot
2019-10-30 15:58 ` [PATCH v4 06/11] sched/fair: use load instead of runnable load in load_balance Mel Gorman
2019-10-18 13:26 ` [PATCH v4 07/11] sched/fair: evenly spread tasks when not overloaded Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Spread out tasks evenly " tip-bot2 for Vincent Guittot
2019-10-30 16:03 ` [PATCH v4 07/11] sched/fair: evenly spread tasks " Mel Gorman
2019-10-18 13:26 ` [PATCH v4 08/11] sched/fair: use utilization to select misfit task Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Use " tip-bot2 for Vincent Guittot
2019-10-18 13:26 ` [PATCH v4 09/11] sched/fair: use load instead of runnable load in wakeup path Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Use " tip-bot2 for Vincent Guittot
2019-10-18 13:26 ` [PATCH v4 10/11] sched/fair: optimize find_idlest_group Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Optimize find_idlest_group() tip-bot2 for Vincent Guittot
2019-10-18 13:26 ` [PATCH v4 11/11] sched/fair: rework find_idlest_group Vincent Guittot
2019-10-21 9:12 ` [tip: sched/core] sched/fair: Rework find_idlest_group() tip-bot2 for Vincent Guittot
2019-10-22 16:46 ` [PATCH] sched/fair: fix rework of find_idlest_group() Vincent Guittot
2019-10-23 7:50 ` Chen, Rong A
2019-10-30 16:07 ` Mel Gorman
2019-11-18 17:42 ` [tip: sched/core] sched/fair: Fix " tip-bot2 for Vincent Guittot
2019-11-22 14:37 ` [PATCH] sched/fair: fix " Valentin Schneider
2019-11-25 9:16 ` Vincent Guittot
2019-11-25 11:03 ` Valentin Schneider
2019-11-20 11:58 ` [PATCH v4 11/11] sched/fair: rework find_idlest_group Qais Yousef
2019-11-20 13:21 ` Vincent Guittot [this message]
2019-11-20 16:53 ` Vincent Guittot
2019-11-20 17:34 ` Qais Yousef
2019-11-20 17:43 ` Vincent Guittot
2019-11-20 18:10 ` Qais Yousef
2019-11-20 18:20 ` Vincent Guittot
2019-11-20 18:27 ` Qais Yousef
2019-11-20 19:28 ` Vincent Guittot
2019-11-20 19:55 ` Qais Yousef
2019-11-21 14:58 ` Qais Yousef
2019-11-22 14:34 ` Valentin Schneider
2019-11-25 9:59 ` Vincent Guittot
2019-11-25 11:13 ` Valentin Schneider
2019-10-21 7:50 ` [PATCH v4 00/10] sched/fair: rework the CFS load balance Ingo Molnar
2019-10-21 8:44 ` Vincent Guittot
2019-10-21 12:56 ` Phil Auld
2019-10-24 12:38 ` Phil Auld
2019-10-24 13:46 ` Phil Auld
2019-10-24 14:59 ` Vincent Guittot
2019-10-25 13:33 ` Phil Auld
2019-10-28 13:03 ` Vincent Guittot
2019-10-30 14:39 ` Phil Auld
2019-10-30 16:24 ` Dietmar Eggemann
2019-10-30 16:35 ` Valentin Schneider
2019-10-30 17:19 ` Phil Auld
2019-10-30 17:25 ` Valentin Schneider
2019-10-30 17:29 ` Phil Auld
2019-10-30 17:28 ` Vincent Guittot
2019-10-30 17:44 ` Phil Auld
2019-10-30 17:25 ` Vincent Guittot
2019-10-31 13:57 ` Phil Auld
2019-10-31 16:41 ` Vincent Guittot
2019-10-30 16:24 ` Mel Gorman
2019-10-30 16:35 ` Vincent Guittot
2019-11-18 13:15 ` Ingo Molnar
2019-11-25 12:48 ` Valentin Schneider
2020-01-03 16:39 ` Valentin Schneider
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='CAKfTPtDh7HAv2Krx9cRKcA+Zy=erYkykyZZj4=nkRoTEdY=oFw@mail.gmail.com' \
--to=vincent.guittot@linaro.org \
--cc=Morten.Rasmussen@arm.com \
--cc=dietmar.eggemann@arm.com \
--cc=hdanton@sina.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=parth@linux.ibm.com \
--cc=pauld@redhat.com \
--cc=peterz@infradead.org \
--cc=qais.yousef@arm.com \
--cc=quentin.perret@arm.com \
--cc=riel@surriel.com \
--cc=srikar@linux.vnet.ibm.com \
--cc=valentin.schneider@arm.com \
/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).