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Douglas Anderson 4503261ab9 watchdog/perf: more properly prevent false positives with turbo modes
[ Upstream commit 4379e59fe5 ]

Currently, in the watchdog_overflow_callback() we first check to see if
the watchdog had been touched and _then_ we handle the workaround for
turbo mode.  This order should be reversed.

Specifically, "touching" the hardlockup detector's watchdog should avoid
lockups being detected for one period that should be roughly the same
regardless of whether we're running turbo or not.  That means that we
should do the extra accounting for turbo _before_ we look at (and clear)
the global indicating that we've been touched.

NOTE: this fix is made based on code inspection.  I am not aware of any
reports where the old code would have generated false positives.  That
being said, this order seems more correct and also makes it easier down
the line to share code with the "buddy" hardlockup detector.

Link: https://lkml.kernel.org/r/20230519101840.v5.2.I843b0d1de3e096ba111a179f3adb16d576bef5c7@changeid
Fixes: 7edaeb6841 ("kernel/watchdog: Prevent false positives with turbo modes")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27 08:37:10 +02:00
arch ARM: 9303/1: kprobes: avoid missing-declaration warnings 2023-07-27 08:37:06 +02:00
block block/blk-iocost (gcc13): keep large values in a new enum 2023-06-14 10:59:54 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:11:22 +02:00
crypto KEYS: asymmetric: Copy sig and digest in public_key_verify_signature() 2023-06-21 15:44:08 +02:00
Documentation Remove DECnet support from kernel 2023-06-21 15:44:10 +02:00
drivers wifi: rsi: Do not set MMC_PM_KEEP_POWER in shutdown 2023-07-27 08:37:09 +02:00
fs pstore/ram: Add check for kstrdup 2023-07-27 08:37:06 +02:00
include watchdog/perf: define dummy watchdog_update_hrtimer_threshold() on correct config 2023-07-27 08:37:10 +02:00
init init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash 2022-12-08 11:22:59 +01:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:23:06 +01:00
kernel watchdog/perf: more properly prevent false positives with turbo modes 2023-07-27 08:37:10 +02:00
lib test_firmware: fix a memory leak with reqs buffer 2023-06-21 15:44:08 +02:00
LICENSES
mm mm: make wait_on_page_writeback() wait for multiple pending writebacks 2023-06-28 10:18:42 +02:00
net nfc: llcp: fix possible use of uninitialized variable in nfc_llcp_send_connect() 2023-07-27 08:37:07 +02:00
samples samples/bpf: Fix buffer overflow in tcp_basertt 2023-07-27 08:37:07 +02:00
scripts scripts/tags.sh: Resolve gtags empty index generation 2023-07-27 08:37:03 +02:00
security ima: Fix build warnings 2023-07-27 08:37:06 +02:00
sound ASoC: nau8824: Add quirk to active-high jack-detect 2023-06-28 10:18:41 +02:00
tools selftests/ptp: Fix timestamp printf format for PTP_SYS_OFFSET 2023-06-21 15:44:12 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: Destroy target device if coalesced MMIO unregistration fails 2023-03-11 16:44:01 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Remove DECnet support from kernel 2023-06-21 15:44:10 +02:00
Makefile Linux 5.4.250 2023-07-24 19:10:53 +02:00
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.