iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
1,220,968 Commits 104 Branches 1,843 Tags 5.7 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
9715ed501b
Go to file
Frederic Weisbecker 9715ed501b rcu/tasks: Handle new PF_IDLE semantics 
The commit:

	cff9b2332a ("kernel/sched: Modify initial boot task idle setup")

has changed the semantics of what is to be considered an idle task in
such a way that CPU boot code preceding the actual idle loop is excluded
from it.

This has however introduced new potential RCU-tasks stalls when either:

1) Grace period is started before init/0 had a chance to set PF_IDLE,
   keeping it stuck in the holdout list until idle ever schedules.

2) Grace period is started when some possible CPUs have never been
   online, keeping their idle tasks stuck in the holdout list until the
   CPU ever boots up.

3) Similar to 1) but with secondary CPUs: Grace period is started
   concurrently with secondary CPU booting, putting its idle task in
   the holdout list because PF_IDLE isn't yet observed on it. It stays
   then stuck in the holdout list until that CPU ever schedules. The
   effect is mitigated here by the hotplug AP thread that must run to
   bring the CPU up.

Fix this with handling the new semantics of PF_IDLE, keeping in mind
that it may or may not be set on an idle task. Take advantage of that to
strengthen the coverage of an RCU-tasks quiescent state within an idle
task, excluding the CPU boot code from it. Only the code running within
the idle loop is now a quiescent state, along with offline CPUs.

Fixes: cff9b2332a ("kernel/sched: Modify initial boot task idle setup")
Suggested-by: Joel Fernandes <joel@joelfernandes.org>
Suggested-by: Paul E . McKenney" <paulmck@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2023-11-01 22:03:56 +01:00
arch RCU pull request for v6.7 2023-10-30 18:01:41 -10:00
block vfs-6.7.super 2023-10-30 08:59:05 -10:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto KEYS: asymmetric: Fix sign/verify on pkcs1pad without a hash 2023-10-18 12:27:10 +08:00
Documentation RCU pull request for v6.7 2023-10-30 18:01:41 -10:00
drivers X86 core code updates: 2023-10-30 17:37:47 -10:00
fs Initial bcachefs pull request for 6.7-rc1 2023-10-30 11:09:38 -10:00
include RCU pull request for v6.7 2023-10-30 18:01:41 -10:00
init - A bunch of improvements, cleanups and fixlets to the SRSO mitigation 2023-10-30 11:48:49 -10:00
io_uring vfs-6.7.misc 2023-10-30 09:14:19 -10:00
ipc ipc: convert to new timestamp accessors 2023-10-18 14:08:30 +02:00
kernel rcu/tasks: Handle new PF_IDLE semantics 2023-11-01 22:03:56 +01:00
lib Scheduler changes for v6.7 are: 2023-10-30 13:12:15 -10:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm RCU pull request for v6.7 2023-10-30 18:01:41 -10:00
net NFSD 6.7 Release Notes 2023-10-30 10:12:29 -10:00
rust rust: docs: fix logo replacement 2023-10-19 16:40:00 +02:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts RCU pull request for v6.7 2023-10-30 18:01:41 -10:00
security vfs-6.7.ctime 2023-10-30 09:47:13 -10:00
sound vfs-6.7.iov_iter 2023-10-30 09:24:21 -10:00
tools RCU pull request for v6.7 2023-10-30 18:01:41 -10:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
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 - A new EDAC driver for Xilinx's Versal integrated memory controller 2023-10-30 11:45:36 -10:00
Makefile Linux 6.6 2023-10-29 16:31:08 -10:00
README

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 Restructured Text 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.