kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-10 20:48:12 +00:00
Code Issues Releases Packages Activity
No description
1,309,169 commits 117 branches 5,827 tags 6.3 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Zhongqiu Han 8e113df990 sched: idle: Optimize the generic idle loop by removing needless memory barrier 
The memory barrier rmb() in generic idle loop do_idle() function is not
needed, it doesn't order any load instruction, just remove it as needless
rmb() can cause performance impact.

The rmb() was introduced by the tglx/history.git commit f2f1b44c75c4
("[PATCH] Remove RCU abuse in cpu_idle()") to order the loads between
cpu_idle_map and pm_idle. It pairs with wmb() in function cpu_idle_wait().

And then with the removal of cpu_idle_state in function cpu_idle() and
wmb() in function cpu_idle_wait() in commit 783e391b7b ("x86: Simplify
cpu_idle_wait"), rmb() no longer has a reason to exist.

After that, commit d166991234 ("idle: Implement generic idle function")
implemented a generic idle function cpu_idle_loop() which resembles the
functionality found in arch/. And it retained the rmb() in generic idle
loop in file kernel/cpu/idle.c.

And at last, commit cf37b6b484 ("sched/idle: Move cpu/idle.c to
sched/idle.c") moved cpu/idle.c to sched/idle.c. And commit c1de45ca83
("sched/idle: Add support for tasks that inject idle") renamed function
cpu_idle_loop() to do_idle().

History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20241009093745.9504-1-quic_zhonhan@quicinc.com
History 2024-10-14 12:52:40 +02:00
arch ARM64: 2024-10-06 10:53:28 -07:00
block block-6.12-20241004 2024-10-04 10:43:44 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
Documentation platform-drivers-x86 for v6.12-2 2024-10-06 11:11:01 -07:00
drivers platform-drivers-x86 for v6.12-2 2024-10-06 11:11:01 -07:00
fs fs/bcachefs: Fix __wait_on_freeing_inode() definition of waitqueue entry 2024-10-09 10:00:09 +02:00
include Merge branch 'tip/sched/urgent' 2024-10-14 12:52:39 +02:00
init cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig 2024-09-26 21:27:27 +02:00
io_uring io_uring/net: harden multishot termination case for recv 2024-09-30 08:26:59 -06:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel sched: idle: Optimize the generic idle loop by removing needless memory barrier 2024-10-14 12:52:40 +02:00
lib slab fixes for 6.12-rc1 2024-10-04 12:05:39 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm, slab: suppress warnings in test_leak_destroy kunit test 2024-10-02 16:28:46 +02:00
net Including fixes from ieee802154, bluetooth and netfilter. 2024-10-03 09:44:00 -07:00
rust rust: kunit: use C-string literals to clean warning 2024-10-01 23:46:42 +02:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts kbuild: deb-pkg: Remove blank first line from maint scripts 2024-10-07 02:36:38 +09:00
security hardening fixes for v6.12-rc2 2024-10-05 10:19:14 -07:00
sound sound fixes for 6.12-rc2 2024-10-04 11:29:46 -07:00
tools ARM64: 2024-10-06 10:53:28 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt sched/fair: Fix external p->on_rq users 2024-10-14 09:14:35 +02:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap Summary 2024-09-24 11:08:40 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Mark powerpc spufs as orphaned 2024-08-19 21:27:56 +10:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS platform-drivers-x86 for v6.12-2 2024-10-06 11:11:01 -07:00
Makefile Linux 6.12-rc2 2024-10-06 15:32:27 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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.