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

[Andres Oportus]

Tested-by: Andres Oportus <andresoportus@xxxxxxxxxx>

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
> >
> >