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Thomas Gleixner f944ffcbc2 watchdog/perf: properly initialize the turbo mode timestamp and rearm counter
For systems on which the performance counter can expire early due to turbo
modes the watchdog handler has a safety net in place which validates that
since the last watchdog event there has at least 4/5th of the watchdog
period elapsed.

This works reliably only after the first watchdog event because the per
CPU variable which holds the timestamp of the last event is never
initialized.

So a first spurious event will validate against a timestamp of 0 which
results in a delta which is likely to be way over the 4/5 threshold of the
period.  As this might happen before the first watchdog hrtimer event
increments the watchdog counter, this can lead to false positives.

Fix this by initializing the timestamp before enabling the hardware event.
Reset the rearm counter as well, as that might be non zero after the
watchdog was disabled and reenabled.

Link: https://lkml.kernel.org/r/87frsfu15a.ffs@tglx
Fixes: 7edaeb6841 ("kernel/watchdog: Prevent false positives with turbo modes")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17 21:11:34 -07:00
arch init/modpost: conditionally check section mismatch to __meminit* 2024-07-12 16:39:52 -07:00
block block: unmap and free user mapped integrity via submitter 2024-06-12 11:00:50 -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 The core gains placeholders for recently added functions when CONFIG_I2C 2024-06-23 11:06:01 -04:00
drivers kernel-wide: fix spelling mistakes like "assocative" -> "associative" 2024-06-28 19:36:28 -07:00
fs nilfs2: Constify struct kobj_type 2024-07-12 16:39:52 -07:00
include init/modpost: conditionally check section mismatch to __meminit* 2024-07-12 16:39:52 -07:00
init gcc: disable '-Warray-bounds' for gcc-9 2024-06-15 10:43:04 -07:00
io_uring io_uring/rsrc: fix incorrect assignment of iter->nr_segs in io_import_fixed 2024-06-20 06:51:56 -06:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel watchdog/perf: properly initialize the turbo mode timestamp and rearm counter 2024-07-17 21:11:34 -07:00
lib lib/bch.c: use swap() to improve code 2024-07-12 16:39:53 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memblock: fix fragility in checks for unset node ID 2024-06-23 10:32:24 -04:00
net kernel-wide: fix spelling mistakes like "assocative" -> "associative" 2024-06-28 19:36:28 -07:00
rust rust: avoid unused import warning in rusttest 2024-06-11 23:33:28 +02:00
samples kfifo: add missing MODULE_DESCRIPTION() macros 2024-06-28 19:36:29 -07:00
scripts init/modpost: conditionally check section mismatch to __meminit* 2024-07-12 16:39:52 -07:00
security lsm/stable-6.10 PR 20240617 2024-06-17 18:35:12 -07:00
sound ALSA: hda: Use imply for suggesting CONFIG_SERIAL_MULTI_INSTANTIATE 2024-06-21 12:04:19 +02:00
tools selftests: proc: remove unreached code and fix build warning 2024-06-28 19:36:27 -07:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt KVM fixes for 6.10 2024-06-21 08:03:55 -04:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.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: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap bpf-for-netdev 2024-06-14 17:57:10 -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: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
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 cpumask: split out include/linux/cpumask_types.h 2024-06-24 22:25:01 -07:00
Makefile Linux 6.10-rc5 2024-06-23 17:08:54 -04:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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.