kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-12 06:01:58 +00:00
Code Issues Releases Packages Activity
No description
1,144,163 commits 116 branches 5,791 tags 5.6 GiB
  • C 96.9%
  • Assembly 0.9%
  • Rust 0.6%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Sebastian Andrzej Siewior 290e26ec0d tick/common: Align tick period with the HZ tick. 
[ Upstream commit e9523a0d81 ]

With HIGHRES enabled tick_sched_timer() is programmed every jiffy to
expire the timer_list timers. This timer is programmed accurate in
respect to CLOCK_MONOTONIC so that 0 seconds and nanoseconds is the
first tick and the next one is 1000/CONFIG_HZ ms later. For HZ=250 it is
every 4 ms and so based on the current time the next tick can be
computed.

This accuracy broke since the commit mentioned below because the jiffy
based clocksource is initialized with higher accuracy in
read_persistent_wall_and_boot_offset(). This higher accuracy is
inherited during the setup in tick_setup_device(). The timer still fires
every 4ms with HZ=250 but timer is no longer aligned with
CLOCK_MONOTONIC with 0 as it origin but has an offset in the us/ns part
of the timestamp. The offset differs with every boot and makes it
impossible for user land to align with the tick.

Align the tick period with CLOCK_MONOTONIC ensuring that it is always a
multiple of 1000/CONFIG_HZ ms.

Fixes: 857baa87b6 ("sched/clock: Enable sched clock early")
Reported-by: Gusenleitner Klaus <gus@keba.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20230406095735.0_14edn3@linutronix.de
Link: https://lore.kernel.org/r/20230418122639.ikgfvu3f@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2023-05-11 23:03:16 +09:00
arch arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step 2023-05-11 23:03:16 +09:00
block blk-crypto: make blk_crypto_evict_key() more robust 2023-05-11 23:03:01 +09:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: api - Demote BUG_ON() in crypto_unregister_alg() to a WARN_ON() 2023-05-11 23:03:02 +09:00
Documentation ASoC: dt-bindings: qcom,lpass-rx-macro: correct minItems for clocks 2023-05-11 23:03:05 +09:00
drivers drm/i915: Make intel_get_crtc_new_encoder() less oopsy 2023-05-11 23:03:16 +09:00
fs erofs: fix potential overflow calculating xattr_isize 2023-05-11 23:03:07 +09:00
include ACPI: processor: Fix evaluating _PDC method when running as Xen dom0 2023-05-11 23:03:11 +09:00
init gcc: disable '-Warray-bounds' for gcc-13 too 2023-04-26 14:28:43 +02:00
io_uring io_uring: fix memory leak when removing provided buffers 2023-04-13 16:55:31 +02:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel tick/common: Align tick period with the HZ tick. 2023-05-11 23:03:16 +09:00
lib debugobject: Prevent init race with static objects 2023-05-11 23:03:16 +09:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/mempolicy: fix use-after-free of VMA iterator 2023-05-01 08:26:27 +09:00
net bluetooth: Perform careful capability checks in hci_sock_ioctl() 2023-05-01 08:26:27 +09:00
rust rust: kernel: Mark rust_fmt_argument as extern "C" 2023-04-26 14:28:38 +02:00
samples ftrace: Export ftrace_free_filter() to modules 2023-02-01 08:34:37 +01:00
scripts ASN.1: Fix check for strdup() success 2023-04-26 14:28:44 +02:00
security selinux: ensure av_permissions.h is built when needed 2023-05-11 23:03:06 +09:00
sound ASoC: amd: ps: update the acp clock source. 2023-05-11 23:02:59 +09:00
tools tools/x86/kcpuid: Fix avx512bw and avx512lvl fields in Fn00000007 2023-05-11 23:03:07 +09:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Register /dev/kvm as the _very_ last thing during initialization 2023-03-10 09:34:11 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.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: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
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 audit: update the mailing list in MAINTAINERS 2023-02-25 11:25:42 +01:00
Makefile Linux 6.1.27 2023-05-01 08:26:28 +09:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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 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.