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Choonghoon Park f25741f047 ANDROID: sched/fair: Do not sync task util with SD_BALANCE_FORK
When android_rvh_select_task_rq_fair is enabled,
the woken-up new fair task's utilization is always updated in
a wakeup path (wake_up_new_task) although it doesn't have to be.
It is because sync_entity_load_avg() is always called in
select_task_rq_fair() with the hook enabled.

Let's see what happened:

The new task's sched_avg->last_update_time should be 0
unless it is updated in attach_entity_cfs_rq() in the wakeup path.

But because sync_entity_load_avg() is called,
sched_avg->last_update_time is updated with cfs_rq->avg.last_update_time
before attach_entity_cfs_rq() is called.

After updated, post_init_entity_util_avg() is called and the half of
spare capacity of rq which the task is assigned to is set to the task's
utilization.

Finally, update_load_avg() is called and check the task's
sched_avg->last_update_time, and update the task's utilization due to
non-zero last_update_time.

- wake_up_new_task()
  - select_task_rq() <-- task's sched_avg->last_update_time is set
  			 if android_rvh_select_task_rq_fair is enabled.
  - post_init_entity_util_avg() <-- task gets the half of spare cap.
    - attach_entity_cfs_rq()
      - update_load_avg <-- update task's utiliztion because
                            task's sched_avg->last_update_time is not 0.

Make sure not to call sync_entity_load_avg() in select_task_rq_fair()
when SD_BALANCE_FORK is also set with the hook.

Bug: 183306209

Signed-off-by: Choonghoon Park <choong.park@samsung.com>
Change-Id: I1fd70bf3d8e5fe1548f2237afd2d3d81134a68ee
2021-03-22 20:09:56 +09:00
android ANDROID: qcom: Add is_dma_buf_file to ABI 2021-03-20 09:48:47 +00:00
arch ANDROID: GKI: enable KFENCE by setting the sample interval to 500ms 2021-03-19 21:38:56 +01:00
block Merge 5.10.20 into android12-5.10 2021-03-07 12:33:33 +01:00
certs certs: Fix blacklist flag type confusion 2021-03-04 11:37:59 +01:00
crypto This is the 5.10.21 stable release 2021-03-07 12:53:30 +01:00
Documentation FROMGIT: f2fs: add sysfs nodes to get runtime compression stat 2021-03-19 09:05:58 +00:00
drivers ANDROID: usb: typec: tcpci: Migrate restricted vendor hook 2021-03-21 13:24:36 -07:00
fs FROMGIT: f2fs: add sysfs nodes to get runtime compression stat 2021-03-19 09:05:58 +00:00
include ANDROID: usb: typec: tcpci: Migrate restricted vendor hook 2021-03-21 13:24:36 -07:00
init Merge 5.10.20 into android12-5.10 2021-03-07 12:33:33 +01:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel ANDROID: sched/fair: Do not sync task util with SD_BALANCE_FORK 2021-03-22 20:09:56 +09:00
lib ANDROID: vendor_hooks: Add hooks for memory when debug 2021-03-19 04:54:07 +00:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm ANDROID: vendor_hooks: Add hooks for memory when debug 2021-03-19 04:54:07 +00:00
net FROMGIT: selinux: vsock: Set SID for socket returned by accept() 2021-03-22 08:41:33 +00:00
samples watch_queue: Drop references to /dev/watch_queue 2021-03-04 11:37:59 +01:00
scripts Revert "BACKPORT: kasan: remove redundant config option" 2021-03-05 19:33:02 +00:00
security ANDROID: security: selinux: Add vendor hook in avc 2021-03-15 15:37:18 +00:00
sound ANDROID: GKI: sound/usb/card.h: add Android ABI padding to struct snd_usb_endpoint 2021-03-18 16:21:14 +01:00
tools Merge 5.10.20 into android12-5.10 2021-03-07 12:33:33 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() 2021-02-26 10:13:01 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore FROMLIST: kbuild: lto: fix module versioning 2020-12-16 08:56:32 -08:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
build.config.aarch64 ANDROID: enable LLVM_IAS=1 for clang's integrated assembler for aarch64 2020-11-10 12:14:17 -08:00
build.config.allmodconfig ANDROID: allmodconfig: drop openssl from ADDITIONAL_HOST_TOOLS 2021-03-04 20:48:17 +00:00
build.config.allmodconfig.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.allmodconfig.arm ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.allmodconfig.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.amlogic ANDROID: GKI: amlogic: add DTB overlays 2021-02-12 10:08:04 +01:00
build.config.arm ANDROID: ARM: Use zImage instead of Image 2020-11-13 15:56:44 +00:00
build.config.common ANDROID: clang: update to 12.0.3 2021-03-02 20:48:19 +00:00
build.config.db845c ANDROID: db845c: Use FRAGMENT_CONFIG 2021-02-10 06:08:17 +00:00
build.config.gki ANDROID: gki: Removed cf modules from gki_defconfig 2020-02-01 00:27:50 +00:00
build.config.gki_kasan ANDROID: build.config: Disable LTO for KASAN and Kprobes builds 2021-03-08 00:31:49 +00:00
build.config.gki_kasan.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki_kasan.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki_kprobes ANDROID: build.config: Disable LTO for KASAN and Kprobes builds 2021-03-08 00:31:49 +00:00
build.config.gki_kprobes.aarch64 ANDROID: Adding kprobes build configs for Cuttlefish 2021-03-03 02:03:02 +00:00
build.config.gki_kprobes.x86_64 ANDROID: Adding kprobes build configs for Cuttlefish 2021-03-03 02:03:02 +00:00
build.config.gki-debug.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki-debug.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki.aarch64 ANDROID: Add hikey960 build infrastructure file 2021-02-18 23:59:34 +00:00
build.config.gki.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.hikey960 ANDROID: Add hikey960 build infrastructure file 2021-02-18 23:59:34 +00:00
build.config.x86_64 ANDROID: x86: Add objtool to MAKE_GOALS 2021-01-28 22:19:23 +00:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS UPSTREAM: MAINTAINERS: add entry for KFENCE 2021-03-14 08:17:04 +00:00
Makefile ANDROID: Clang LTO: Comment on symbol visibility workaround 2021-03-13 12:38:32 +00:00
README
README.md ANDROID: README: Add requirement for "Bug:" tag for FROMLIST 2020-05-01 15:36:12 -07:00

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.

    • Do not send patches upstream that contain only symbol exports. To be considered for upstream Linux, additions of EXPORT_SYMBOL_GPL() require an in-tree modular driver that uses the symbol -- so include the new driver or changes to an existing driver in the same patchset as the export.
    • When sending patches upstream, the commit message must contain a clear case for why the patch is needed and beneficial to the community. Enabling out-of-tree drivers or functionality is not not a persuasive case.
  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 commit ...) 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 commit 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 commit ...) 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 commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        [joe: 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
    • add a Bug: tag with the Android bug (required for patches not accepted into a maintainer tree)
    • 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)