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Tejun Heo d86adb4fc0 sched_ext: Add cpuperf support
sched_ext currently does not integrate with schedutil. When schedutil is the
governor, frequencies are left unregulated and usually get stuck close to
the highest performance level from running RT tasks.

Add CPU performance monitoring and scaling support by integrating into
schedutil. The following kfuncs are added:

- scx_bpf_cpuperf_cap(): Query the relative performance capacity of
  different CPUs in the system.

- scx_bpf_cpuperf_cur(): Query the current performance level of a CPU
  relative to its max performance.

- scx_bpf_cpuperf_set(): Set the current target performance level of a CPU.

This gives direct control over CPU performance setting to the BPF scheduler.
The only changes on the schedutil side are accounting for the utilization
factor from sched_ext and disabling frequency holding heuristics as it may
not apply well to sched_ext schedulers which may have a lot weaker
connection between tasks and their current / last CPU.

With cpuperf support added, there is no reason to block uclamp. Enable while
at it.

A toy implementation of cpuperf is added to scx_qmap as a demonstration of
the feature.

v2: Ignore cpu_util_cfs_boost() when scx_switched_all() in sugov_get_util()
    to avoid factoring in stale util metric. (Christian)

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Christian Loehle <christian.loehle@arm.com>
2024-06-21 12:37:22 -10:00
arch bpf-next-for-netdev 2024-06-10 18:02:14 -07:00
block blk-throttle: Fix incorrect display of io.max 2024-05-30 19:44:29 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation sched_ext: Documentation: scheduler: Document extensible scheduler class 2024-06-18 10:09:21 -10:00
drivers sched_ext: Add sysrq-S which disables the BPF scheduler 2024-06-18 10:09:18 -10:00
fs bpf: treewide: Align kfunc signatures to prog point-of-view 2024-06-12 11:01:31 -07:00
include sched_ext: Documentation: scheduler: Document extensible scheduler class 2024-06-18 10:09:21 -10:00
init sched_ext: Add vtime-ordered priority queue to dispatch_q's 2024-06-18 10:09:21 -10:00
io_uring io_uring/net: assign kmsg inq/flags before buffer selection 2024-05-30 14:04:37 -06:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel sched_ext: Add cpuperf support 2024-06-21 12:37:22 -10:00
lib sched_ext: Print sched_ext info when dumping stack 2024-06-18 10:09:18 -10:00
LICENSES
mm 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
net bpf: Relax tuple len requirement for sk helpers. 2024-06-14 21:52:39 +02:00
rust LoongArch changes for v6.10 2024-05-22 09:43:07 -07:00
samples bpf-next-for-netdev 2024-05-28 07:27:29 -07:00
scripts kbuild: bpf: Tell pahole to DECL_TAG kfuncs 2024-06-12 11:01:30 -07:00
security tomoyo: update project links 2024-06-03 22:43:11 +09:00
sound ALSA: seq: ump: Fix swapped song position pointer data 2024-05-31 09:51:44 +02:00
tools sched_ext: Add cpuperf support 2024-06-21 12:37:22 -10:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
.clang-format
.cocciconfig
.editorconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap mailmap: update entry for Kees Cook 2024-05-31 08:58:36 -07:00
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild
Kconfig
MAINTAINERS sched_ext: Implement BPF extensible scheduler class 2024-06-18 10:09:17 -10:00
Makefile sched_ext: Add scx_simple and scx_example_qmap example schedulers 2024-06-18 10:09:17 -10:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.