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When the window is advanced to the next boundary, the CPU busy time
trackers need to be advanced and top-task trackers should be flipped.
This rollover needs to be done just once for a cpu per window
advancement, while it could be subject to numerous update_task_ravg
(called utra henceforth) with various tasks spanning window cross over
point. The current code achieves this one-time-rollover only when it
sees a utra called for the currently running task and its time has
crossed over in the new window.
As a result of this rollover being done only
when utra is called for current task, it became mandatory to call
utra on current task before calling utra on a non-current task.
This ensured a proper window rollover i.e. the trackers reset/flipped
if needed prior to calling utra on non-current task which may have
entered its execution in a new window.
Explaining pictorially
old new
ws ms ws wc
| | | |
V V V V
-----|----------------|--------
prev curr
In the above example, a non current task wc may have entered the new
window but prev and curr are still set as per the old window start. The
time from new ws to wc cannot be accounted because curr(_runnable_sum)
hasnt advanced i.e hasn't rolled over. Hence utra is called with the
current task which causes a rollover i.e. it advances prev,
curr(_runnable_sum) pointers amongst other things
old new
ws ms ws wc
| | | |
V V V V
-----|----------------|--------
prev curr
We see utra on current being called,
when a task 'p' is woken up, two update_task_ravg() calls are needed.
update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0);
update_task_ravg(p, rq, TASK_WAKE, wallclock, 0);
when a task 'p' is migrating, three update_task_ravg() calls are needed.
update_task_ravg(task_rq(p)->curr, task_rq(p), TASK_UPDATE, wallclock, 0);
update_task_ravg(dest_rq->curr, dest_rq, TASK_UPDATE, wallclock, 0);
update_task_ravg(p, task_rq(p), TASK_MIGRATE, wallclock, 0);
when a task 'p' is tranferring in/out of rtg
update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0);
update_task_ravg(p, rq, TASK_UPDATE, wallclock, 0);
We can optimize the number of update_task_ravg() calls by allowing to
rollover regardless of utra on current task. The best place to do it is
in update_window_start() right along the code which advances the window
start.
Since the update is not happening on the running task i.e current, the
CPU utilization i.e prev_runnable_sum does not reflect the current task
utilization immediately after the window is rolled over. However
update_task_ravg() is called on the current before presenting the
utilization to the governor. So there should not be any impact on
the final frequency selection.
A TASK_WAKE of a iowaited task needs to terminate the accumulation of
iowait time on the cpu where the task had slept. The mark_start of the
idle task is advanced and the "advanced" time is accounted as cpu busy
time. For this situation alone call utra on idle task if an iowaited
task is waking up.
Change-Id: Ifb771b41bd62f3c748035bf1e5e5ad7912b400f4
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Abhijeet Dharmapurikar <quic_adharmap@quicinc.com>
Signed-off-by: Shaleen Agrawal <quic_shalagra@quicinc.com>
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|---|---|---|
| android | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| Android.bp | ||
| BUILD.bazel | ||
| build.config.aarch64 | ||
| build.config.allmodconfig | ||
| build.config.allmodconfig.aarch64 | ||
| build.config.allmodconfig.arm | ||
| build.config.allmodconfig.x86_64 | ||
| build.config.amlogic | ||
| build.config.arm | ||
| build.config.common | ||
| build.config.constants | ||
| build.config.db845c | ||
| build.config.gki | ||
| build.config.gki_consolidate.aarch64 | ||
| build.config.gki_kasan | ||
| build.config.gki_kasan.aarch64 | ||
| build.config.gki_kasan.x86_64 | ||
| build.config.gki_kprobes | ||
| build.config.gki_kprobes.aarch64 | ||
| build.config.gki_kprobes.x86_64 | ||
| build.config.gki-debug.aarch64 | ||
| build.config.gki-debug.x86_64 | ||
| build.config.gki.aarch64 | ||
| build.config.gki.x86_64 | ||
| build.config.khwasan | ||
| build.config.msm.common | ||
| build.config.msm.gki | ||
| build.config.msm.pineapple | ||
| build.config.rockpi4 | ||
| build.config.x86_64 | ||
| build.targets | ||
| COPYING | ||
| CREDITS | ||
| files_gki_aarch64.txt | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.ext | ||
| MAINTAINERS | ||
| Makefile | ||
| modules.list.msm.pineapple | ||
| modules.vendor_blocklist.msm.pineapple | ||
| OWNERS | ||
| OWNERS_DrNo | ||
| README | ||
| README.md | ||
How do I submit patches to Android Common Kernels
-
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.
- Do not send patches upstream that contain only symbol exports. To be considered for upstream Linux,
additions of
-
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
scripts/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:, orANDROID:. - 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
- tag the patch subject with
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 ofUPSTREAM:.- use the same tags as
UPSTREAM: - add comments about the changes under the
(cherry picked from commit ...)line - Example:
- use the same tags as
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 uselinux-nextfor example). - if changes were required, use
BACKPORT: FROMGIT: - Example:
- if the commit message in the maintainer tree is
- tag the patch subject with
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:
- tag the patch subject with
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:
- tag the patch subject with
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)
- tag the patch subject with