Re: [PATCH 0/6 v6] sched: reflect sched_entity move into task_group's load

[Vincent Guittot]

On 22 November 2016 at 19:50, Andres Oportus <andresoportus@xxxxxxxxxx> wrote:
> Tested-by: Andres Oportus <andresoportus@xxxxxxxxxx>

Thanks

>
> On Tue, Nov 22, 2016 at 9:55 AM, Andres Oportus
> <andresoportus@xxxxxxxxxx> wrote:
>>
>> On Tue, Nov 22, 2016 at 9:52 AM, Andres Oportus
>> <andresoportus@xxxxxxxxxx> wrote:
>> >
>> > I have back-ported these patches into Android with 4.4 kernel and tested
>> > them on a Hikey device [1].  Back-ported patches used are enclosed.
>> > I see equal or better performance across all tests.
>> >
>> > PELT below refers to https://android.googlesource.com/kernel/hikey-linaro at
>> > android-hikey-linaro-4.4 caae63389787850e633eef67526443729c18451c
>> > and WALT disabled (Android with PELT).
>> > PELT+fixes refers to PELT + Vincent's patches back-ported.
>> >
>> > These are tests run using the Vellamo app [2], higher scores are better:
>> >
>> > Test                   PELT      PELT+fixes   Delta
>> > MT Linpack native      126       131           3.97%
>> > MT Linpack java        173       175           1.16%
>> > MT Stream 5.10         158       158           0.00%
>> > Membench               212       214           0.94%
>> > Sysbench               174       196          12.64%
>> > Parsec                 202       207           2.48%
>> >
>> > These are "Jankbench" tests, real world use cases of special interest to
>> > Android.  Xth frame percentile indicates X % of frames rendered in Y ms
>> > or less. Lower is better.
>> >
>> > Test                            PELT    PELT+fixes  Delta
>> > listview scroll 90%             13.87   13.66       -1.54%
>> > listview scroll 95%             14.80   14.58       -1.51%
>> > listview scroll 99%             17.43   17.00       -2.53%
>> > image listview scroll 90%       14.17   14.04       -0.93%
>> > image listview scroll 95%       15.13   14.90       -1.54%
>> > image listview scroll 99%       17.43   17.08       -2.05%
>> > shadow grid 90%                 16.40   16.28       -0.74%
>> > shadow grid 95%                 17.23   17.06       -1.00%
>> > shadow grid 99%                 23.07   23.44        1.58%
>> > hi-hitrate text render 90%      28.77   28.62       -0.52%
>> > hi-hitrate text render 95%      31.60   31.48       -0.38%
>> > hi-hitrate text render 96%      41.53   41.10       -1.05%
>> > low-hitrate text render 90%     28.97   28.66       -1.08%
>> > low-hitrate text render 95%     32.10   31.66       -1.39%
>> > low-hitrate text render 99%     41.70   41.38       -0.77%
>> >
>> > Andres
>> >
>> > [1] http://www.96boards.org/product/hikey
>> > [2] https://play.google.com/store/apps/details?id=com.quicinc.vellamo
>> >
>> >
>> >> From: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
>> >> Date: Tue, Nov 8, 2016 at 12:26 AM
>> >> Subject: [PATCH 0/6 v6] sched: reflect sched_entity move into task_group's load
>> >> To: peterz@xxxxxxxxxxxxx, mingo@xxxxxxxxxx,
>> >> linux-kernel@xxxxxxxxxxxxxxx, dietmar.eggemann@xxxxxxx
>> >> Cc: yuyang.du@xxxxxxxxx, Morten.Rasmussen@xxxxxxx, pjt@xxxxxxxxxx,
>> >> bsegall@xxxxxxxxxx, kernellwp@xxxxxxxxx, Vincent Guittot
>> >> <vincent.guittot@xxxxxxxxxx>
>> >>
>> >>
>> >> Ensure that the move of a sched_entity will be reflected in load and
>> >> utilization of the task_group hierarchy.
>> >>
>> >> When a sched_entity moves between groups or CPUs, load and utilization
>> >> of cfs_rq don't reflect the changes immediately but converge to new values.
>> >> As a result, the metrics are no more aligned with the new balance of the
>> >> load in the system and next decisions will have a biased view.
>> >>
>> >> This patchset synchronizes load/utilization of sched_entity with its child
>> >> cfs_rq (se->my-q) only when tasks move to/from child cfs_rq:
>> >> -move between task group
>> >> -migration between CPUs
>> >> Otherwise, PELT is updated as usual.
>> >>
>> >> This version doesn't include any changes related to discussion that have
>> >> started during the review of the previous version about:
>> >> - encapsulate the sequence for changing the property of a task
>> >> - remove a cfs_rq from list during update_blocked_averages
>> >> These topics don't gain anything from being added in this patchset as they
>> >> are fairly independent and deserve a separate patch.
>> >>
>> >> Changes since v5:
>> >> - factorize detach entity like for attach
>> >> - fix add_positive
>> >> - Fixed few coding style
>> >>
>> >> Changes since v4:
>> >> - minor typo and commit message changes
>> >> - move call to cfs_rq_clock_task(cfs_rq) in post_init_entity_util_avg
>> >>
>> >> Changes since v3:
>> >> - Replaced the 2 arguments of update_load_avg by 1 flags argument
>> >> - Propagated move in runnable_load_avg when sched_entity is already on_rq
>> >> - Ensure that intermediate value will not reach memory when updating load and
>> >>   utilization
>> >> - Optimize the the calculation of load_avg of the sched_entity
>> >> - Fixed some typo
>> >>
>> >> Changes since v2:
>> >> - Propagate both utilization and load
>> >> - Synced sched_entity and se->my_q instead of adding the delta
>> >>
>> >> Changes since v1:
>> >> - This patch needs the patch that fixes issue with rq->leaf_cfs_rq_list
>> >>   "sched: fix hierarchical order in rq->leaf_cfs_rq_list" in order to work
>> >>   correctly. I haven't sent them as a single patchset because the fix is
>> >>   independent of this one
>> >> - Merge some functions that are always used together
>> >> - During update of blocked load, ensure that the sched_entity is synced
>> >>   with the cfs_rq applying changes
>> >> - Fix an issue when task changes its cpu affinity
>> >>
>> >> Vincent Guittot (6):
>> >>   sched: factorize attach/detach entity
>> >>   sched: fix hierarchical order in rq->leaf_cfs_rq_list
>> >>   sched: factorize PELT update
>> >>   sched: propagate load during synchronous attach/detach
>> >>   sched: propagate asynchrous detach
>> >>   sched: fix task group initialization
>> >>
>> >>  kernel/sched/core.c  |   1 +
>> >>  kernel/sched/fair.c  | 393 ++++++++++++++++++++++++++++++++++++++++-----------
>> >>  kernel/sched/sched.h |   2 +
>> >>  3 files changed, 316 insertions(+), 80 deletions(-)
>> >>
>> >> --
>> >> 2.7.4
>> >
>> >