This is the initial pull request of sched_ext. The v7 patchset
(https://lkml.kernel.org/r/20240618212056.2833381-1-tj@kernel.org) is
applied on top of tip/sched/core + bpf/master as of Jun 18th.
tip/sched/core 793a62823d1c ("sched/core: Drop spinlocks on contention iff kernel is preempti
ble")
bpf/master f6afdaf72a ("Merge branch 'bpf-support-resilient-split-btf'")
Since then, the following pulls were made:
- v6.11-rc1 is pulled to keep up with the mainline.
- tip/sched/core was pulled several times:
- 7b9f6c864a, 0df340ceae, 5ac998574f, 0b1777f0fa: To resolve
conflicts. See each commit for details on conflicts and their
resolutions.
- d7b01aef9d: To receive fd03c5b858 ("sched: Rework pick_next_task()")
and related commits. @prev in added to sched_class->put_prev_task() and
put_prev_task() is reordered after ->pick_task(), which makes
sched_class->switch_class() unnecessary. The follow-up commits update
sched_ext accordingly and drop sched_class->switch_class().
- bpf/master was pulled to receive baebe9aaba ("bpf: allow passing struct
bpf_iter_<type> as kfunc arguments") and related changes in preparation
for the DSQ iterator patchset
To obtain the net sched_ext changes, diff against:
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git for-6.12-base
which is the merge of:
tip/sched/core bc9057da1a ("sched/cpufreq: Use NSEC_PER_MSEC for deadline task")
bpf/master 2ad6d23f46 ("selftests/bpf: Do not update vmlinux.h unnecessarily")
Since the v7 patchset, the following changes were made:
- cpuperf support which was a part of the v6 patchset was posted separately
and then applied after reviews.
- cgroup support which was a part of the v6 patchset was posted seprately,
iterated and then applied.
- Improve integration with sched core.
- Double locking usage in migration paths dropped. Depend on
TASK_ON_RQ_MIGRATING synchronization instead.
- The BPF scheduler couldn't directly dispatch to the local DSQ of another
CPU using a SCX_DSQ_LOCAL_ON verdict. This caused difficulties around
handling non-wakeup enqueues. Updated so that SCX_DSQ_LOCAL_ON can be used
in the enqueue path too.
- DSQ iterator which was a part of the v6 patchset was posted separately.
The iterator itself was applied after a couple revisions. The associated
selective consumption kfunc can use further improvements and is still
being worked on.
- scx_bpf_dispatch[_vtime]_from_dsq() added to increase flexibility. A task
can now be transferred between two DSQs from almost any context. This
involved significant refactoring of migration code.
- Various fixes and improvements.
As the branch is based on top of tip/sched/core + bpf/master, please merge
after both are applied.
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Merge tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext support from Tejun Heo:
"This implements a new scheduler class called ‘ext_sched_class’, or
sched_ext, which allows scheduling policies to be implemented as BPF
programs.
The goals of this are:
- Ease of experimentation and exploration: Enabling rapid iteration
of new scheduling policies.
- Customization: Building application-specific schedulers which
implement policies that are not applicable to general-purpose
schedulers.
- Rapid scheduler deployments: Non-disruptive swap outs of scheduling
policies in production environments"
See individual commits for more documentation, but also the cover letter
for the latest series:
Link: https://lore.kernel.org/all/20240618212056.2833381-1-tj@kernel.org/
* tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (110 commits)
sched: Move update_other_load_avgs() to kernel/sched/pelt.c
sched_ext: Don't trigger ops.quiescent/runnable() on migrations
sched_ext: Synchronize bypass state changes with rq lock
scx_qmap: Implement highpri boosting
sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()
sched_ext: Compact struct bpf_iter_scx_dsq_kern
sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq()
sched_ext: Move consume_local_task() upward
sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq()
sched_ext: Reorder args for consume_local/remote_task()
sched_ext: Restructure dispatch_to_local_dsq()
sched_ext: Fix processs_ddsp_deferred_locals() by unifying DTL_INVALID handling
sched_ext: Make find_dsq_for_dispatch() handle SCX_DSQ_LOCAL_ON
sched_ext: Refactor consume_remote_task()
sched_ext: Rename scx_kfunc_set_sleepable to unlocked and relocate
sched_ext: Add missing static to scx_dump_data
sched_ext: Add missing static to scx_has_op[]
sched_ext: Temporarily work around pick_task_scx() being called without balance_scx()
sched_ext: Add a cgroup scheduler which uses flattened hierarchy
sched_ext: Add cgroup support
...
Add Documentation/scheduler/sched-ext.rst which gives a high-level overview
and pointers to the examples.
v6: - Add paragraph explaining debug dump.
v5: - Updated to reflect /sys/kernel interface change. Kconfig options
added.
v4: - README improved, reformatted in markdown and renamed to README.md.
v3: - Added tools/sched_ext/README.
- Dropped _example prefix from scheduler names.
v2: - Apply minor edits suggested by Bagas. Caveats section dropped as all
of them are addressed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
To gather the architecture requirements of the "private/global
expedited" membarrier commands. The file will be expanded to
integrate further information about the membarrier syscall (as
needed/desired in the future). While at it, amend some related
inline comments in the membarrier codebase.
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20240131144936.29190-3-parri.andrea@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
changes include:
- Some significant additions to the memory-management documentation
- Some improvements to navigation in the HTML-rendered docs
- More Spanish and Chinese translations
...and the usual set of typo fixes and such.
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Merge tag 'docs-6.3' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"It has been a moderately calm cycle for documentation; the significant
changes include:
- Some significant additions to the memory-management documentation
- Some improvements to navigation in the HTML-rendered docs
- More Spanish and Chinese translations
... and the usual set of typo fixes and such"
* tag 'docs-6.3' of git://git.lwn.net/linux: (68 commits)
Documentation/watchdog/hpwdt: Fix Format
Documentation/watchdog/hpwdt: Fix Reference
Documentation: core-api: padata: correct spelling
docs/mm: Physical Memory: correct spelling in reference to CONFIG_PAGE_EXTENSION
docs: Use HTML comments for the kernel-toc SPDX line
docs: Add more information to the HTML sidebar
Documentation: KVM: Update AMD memory encryption link
printk: Document that CONFIG_BOOT_PRINTK_DELAY required for boot_delay=
Documentation: userspace-api: correct spelling
Documentation: sparc: correct spelling
Documentation: driver-api: correct spelling
Documentation: admin-guide: correct spelling
docs: add workload-tracing document to admin-guide
docs/admin-guide/mm: remove useless markup
docs/mm: remove useless markup
docs/mm: Physical Memory: remove useless markup
docs/sp_SP: Add process magic-number translation
docs: ftrace: always use canonical ftrace path
Doc/damon: fix the data path error
dma-buf: Add "dma-buf" to title of documentation
...
Some documents that listed on subsystem-apis have 'Linux' or 'The Linux'
title prefixes. It's duplicated information, and makes finding the
document of interest with human eyes not easy. Remove the prefixes from
the titles.
Signed-off-by: SeongJae Park <sj@kernel.org>
Acked-by: Iwona Winiarska <iwona.winiarska@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20230122184834.181977-1-sj@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add a document explaining the util clamp feature: what it is and
how to use it. The new document hopefully covers everything one needs to
know about uclamp.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20221216235716.201923-1-qyousef@layalina.io
Cc: Jonathan Corbet <corbet@lwn.net>
- Cleanups for SCHED_DEADLINE
- Tracing updates/fixes
- CPU Accounting fixes
- First wave of changes to optimize the overhead of the scheduler build,
from the fast-headers tree - including placeholder *_api.h headers for
later header split-ups.
- Preempt-dynamic using static_branch() for ARM64
- Isolation housekeeping mask rework; preperatory for further changes
- NUMA-balancing: deal with CPU-less nodes
- NUMA-balancing: tune systems that have multiple LLC cache domains per node (eg. AMD)
- Updates to RSEQ UAPI in preparation for glibc usage
- Lots of RSEQ/selftests, for same
- Add Suren as PSI co-maintainer
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Cleanups for SCHED_DEADLINE
- Tracing updates/fixes
- CPU Accounting fixes
- First wave of changes to optimize the overhead of the scheduler
build, from the fast-headers tree - including placeholder *_api.h
headers for later header split-ups.
- Preempt-dynamic using static_branch() for ARM64
- Isolation housekeeping mask rework; preperatory for further changes
- NUMA-balancing: deal with CPU-less nodes
- NUMA-balancing: tune systems that have multiple LLC cache domains per
node (eg. AMD)
- Updates to RSEQ UAPI in preparation for glibc usage
- Lots of RSEQ/selftests, for same
- Add Suren as PSI co-maintainer
* tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits)
sched/headers: ARM needs asm/paravirt_api_clock.h too
sched/numa: Fix boot crash on arm64 systems
headers/prep: Fix header to build standalone: <linux/psi.h>
sched/headers: Only include <linux/entry-common.h> when CONFIG_GENERIC_ENTRY=y
cgroup: Fix suspicious rcu_dereference_check() usage warning
sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers
sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains
sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity()
sched/deadline,rt: Remove unused functions for !CONFIG_SMP
sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistently
sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy()
sched/deadline: Move bandwidth mgmt and reclaim functions into sched class source file
sched/deadline: Remove unused def_dl_bandwidth
sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE
sched/tracing: Don't re-read p->state when emitting sched_switch event
sched/rt: Plug rt_mutex_setprio() vs push_rt_task() race
sched/cpuacct: Remove redundant RCU read lock
sched/cpuacct: Optimize away RCU read lock
sched/cpuacct: Fix charge percpu cpuusage
sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies
...
All other scheduler documents have been converted to *.rst. Let's do
the same for schedutil.txt.
Also fixed some typos.
Signed-off-by: Tang Yizhou <tangyizhou@huawei.com>
Link: https://lore.kernel.org/r/20220312070751.16844-1-tangyizhou@huawei.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
After commit 8a99b6833c ("sched: Move SCHED_DEBUG sysctl to
debugfs"), some NUMA balancing sysctls enclosed with SCHED_DEBUG has
been moved to debugfs. This patch move the document for these
sysctls from
Documentation/admin-guide/sysctl/kernel.rst
to
Documentation/scheduler/sched-debug.rst
to make the document consistent with the code.
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lkml.kernel.org/r/20220210052514.3038279-1-ying.huang@intel.com
Add some documentation detailing the concepts, requirements and
implementation of capacity aware scheduling across the different scheduler
classes.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200731192016.7484-3-valentin.schneider@arm.com
There are a number of driver-specific descriptions that contain a
mix of userspace and kernelspace documentation. Just like we did
with other similar subsystems, add them at the driver-api
groupset, but don't move the directories.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
In order to prepare to add them to the Kernel API book,
convert the files to ReST format.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
