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Filename Latest commit message Latest commit date
Patrick Bellasi d82457153c UPSTREAM: sched/fair/util_est: Implement faster ramp-up EWMA on utilization increases
The estimated utilization for a task:

   util_est = max(util_avg, est.enqueue, est.ewma)

is defined based on:

 - util_avg: the PELT defined utilization
 - est.enqueued: the util_avg at the end of the last activation
 - est.ewma:     a exponential moving average on the est.enqueued samples

According to this definition, when a task suddenly changes its bandwidth
requirements from small to big, the EWMA will need to collect multiple
samples before converging up to track the new big utilization.

This slow convergence towards bigger utilization values is not
aligned to the default scheduler behavior, which is to optimize for
performance. Moreover, the est.ewma component fails to compensate for
temporarely utilization drops which spans just few est.enqueued samples.

To let util_est do a better job in the scenario depicted above, change
its definition by making util_est directly follow upward motion and
only decay the est.ewma on downward.

Bug: 120440300
Signed-off-by: Patrick Bellasi <patrick.bellasi@matbug.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <qperret@google.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191023205630.14469-1-patrick.bellasi@matbug.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit b8c96361402aa3e74ad48ceef18aed99153d8da8)
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Change-Id: Iaa75dec917748375d9043c3ebf21bf272299c8dd
2020-10-26 12:24:35 +00:00
android ANDROID: GKI: Update abi_gki_aarch64_exynos 2020-10-23 15:35:44 +00:00
arch ANDROID: kbuild: disable GCOV with CFI 2020-10-23 06:43:31 +00:00
block This is the 5.4.59 stable release 2020-08-19 08:40:57 +02:00
certs
crypto Revert "ANDROID: Revert: Merge 5.4.60 into android11-5.4" 2020-08-23 13:12:51 +02:00
Documentation FROMLIST: power: supply: core: property to control reverse charge 2020-09-01 17:57:03 +00:00
drivers ANDROID: PCI: dwc: export symbols for ep driver 2020-10-23 08:44:15 +09:00
fs FROMGIT: mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary 2020-09-15 09:34:00 -07:00
include BACKPORT: FROMLIST: iommu/io-pgtable-arm-v7s: Extend PA34 for MediaTek 2020-10-22 19:44:19 +00:00
init ANDROID: GKI: add fields required to enable CONFIG_TRANSPARENT_HUGEPAGE 2020-10-15 17:21:03 +02:00
ipc
kernel UPSTREAM: sched/fair/util_est: Implement faster ramp-up EWMA on utilization increases 2020-10-26 12:24:35 +00:00
lib Revert "ANDROID: Revert: Merge 5.4.60 into android11-5.4" 2020-08-23 13:12:51 +02:00
LICENSES
mm ANDROID: GKI: add fields required to enable CONFIG_TRANSPARENT_HUGEPAGE 2020-10-15 17:21:03 +02:00
net Revert "Revert "BACKPORT: net: core: use listified Rx for GRO_NORMAL in napi_gro_receive()"" 2020-09-10 11:56:32 +00:00
samples This is the 5.4.59 stable release 2020-08-19 08:40:57 +02:00
scripts ANDROID: recordmcount: avoid STT_FILE as base for mcount offset relocation 2020-10-22 19:57:13 +00:00
security UPSTREAM: security: allow using Clang's zero initialization for stack variables 2020-09-08 15:12:44 +00:00
sound This is the 5.4.61 stable release 2020-08-26 11:11:38 +02:00
tools This is the 5.4.61 stable release 2020-08-26 11:11:38 +02:00
usr
virt KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set 2020-08-26 10:41:08 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
build.config.aarch64
build.config.allmodconfig ANDROID: GKI: Fix up "do not export symbol_get/put()" commit 2020-08-01 14:28:51 +02:00
build.config.allmodconfig.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.allmodconfig.arm ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.allmodconfig.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.arm
build.config.common ANDROID: Update KMI_GENERATION after KMI change 2020-10-15 10:58:29 -07:00
build.config.db845c ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.gki
build.config.gki-debug.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.gki-debug.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.gki.aarch64 ANDROID: Drop abi_gki_aarch64_workarounds 2020-10-15 17:21:03 +02:00
build.config.gki.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.gki_kasan ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.gki_kasan.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.gki_kasan.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.hikey960 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 14:50:31 +08:00
build.config.x86_64
COPYING
CREDITS
Kbuild
Kconfig UPSTREAM: kbuild: ensure full rebuild when the compiler is updated 2020-09-24 10:02:38 +00:00
MAINTAINERS This is the 5.4.61 stable release 2020-08-26 11:11:38 +02:00
Makefile UPSTREAM: security: allow using Clang's zero initialization for stack variables 2020-09-08 15:12:44 +00:00
README
README.md

How do I submit patches to Android Common Kernels

  1. BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. These patches will be merged automatically in the corresponding common kernels. If the patch is already in upstream Linux, post a backport of the patch that conforms to the patch requirements below.

  2. LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are fixing an Android-specific bug, these are very unlikely to be accepted unless they have been coordinated with kernel-team@android.com. If you want to proceed, post a patch that conforms to the patch requirements below.

Common Kernel patch requirements

  • All patches must conform to the Linux kernel coding standards and pass script/checkpatch.pl
  • Patches shall not break gki_defconfig or allmodconfig builds for arm, arm64, x86, x86_64 architectures (see https://source.android.com/setup/build/building-kernels)
  • If the patch is not merged from an upstream branch, the subject must be tagged with the type of patch: UPSTREAM:, BACKPORT:, FROMGIT:, FROMLIST:, or ANDROID:.
  • All patches must have a Change-Id: tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html)
  • If an Android bug has been assigned, there must be a Bug: tag.
  • All patches must have a Signed-off-by: tag by the author and the submitter

Additional requirements are listed below based on patch type

Requirements for backports from mainline Linux: UPSTREAM:, BACKPORT:

  • If the patch is a cherry-pick from Linux mainline with no changes at all
    • tag the patch subject with UPSTREAM:.
    • add upstream commit information with a (cherry-picked from ...) line
    • Example:
      • if the upstream commit message is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
    - then Joe Smith would upload the patch for the common kernel as
        UPSTREAM: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry-picked from c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch requires any changes from the upstream version, tag the patch with BACKPORT: instead of UPSTREAM:.
    • use the same tags as UPSTREAM:
    • add comments about the changes under the (cherry-picked from ...) line
    • Example:
        BACKPORT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry-picked from c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        [ Resolved minor conflict in drivers/foo/bar.c ]
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for other backports: FROMGIT:, FROMLIST:,

  • If the patch has been merged into an upstream maintainer tree, but has not yet been merged into Linux mainline
    • tag the patch subject with FROMGIT:
    • add info on where the patch came from as (cherry picked from commit <sha1> <repo> <branch>). This must be a stable maintainer branch (not rebased, so don't use linux-next for example).
    • if changes were required, use BACKPORT: FROMGIT:
    • Example:
      • if the commit message in the maintainer tree is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
    - then Joe Smith would upload the patch for the common kernel as
        FROMGIT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace
         https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch)
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch has been submitted to LKML, but not accepted into any maintainer tree
    • tag the patch subject with FROMLIST:
    • add a Link: tag with a link to the submittal on lore.kernel.org
    • if changes were required, use BACKPORT: FROMLIST:
    • Example:
        FROMLIST: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for Android-specific patches: ANDROID:

  • If the patch is fixing a bug to Android-specific code
    • tag the patch subject with ANDROID:
    • add a Fixes: tag that cites the patch with the bug
    • Example:
        ANDROID: fix android-specific bug in foobar.c

        This is the detailed description of the important fix

        Fixes: 1234abcd2468 ("foobar: add cool feature")
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch is a new feature
    • tag the patch subject with ANDROID:
    • add a Bug: tag with the Android bug (required for android-specific features)