The patch titled
Subject: watchdog/hardlockup: add comments to touch_nmi_watchdog()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
watchdog-hardlockup-add-comments-to-touch_nmi_watchdog.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/watchdog-hardlockup-add-comments-to-touch_nmi_watchdog.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Douglas Anderson <dianders@xxxxxxxxxxxx>
Subject: watchdog/hardlockup: add comments to touch_nmi_watchdog()
Date: Fri, 19 May 2023 10:18:30 -0700
In preparation for the buddy hardlockup detector, add comments to
touch_nmi_watchdog() to make it obvious that it touches the configured
hardlockup detector regardless of whether it's backed by an NMI. Also
note that arch_touch_nmi_watchdog() may not be architecture-specific.
Ideally, we'd like to rename these functions but that is a fairly
disruptive change touching a lot of drivers. After discussion [1] the
plan is to defer this until a good time.
[1] https://lore.kernel.org/r/ZFy0TX1tfhlH8gxj@alley
Link: https://lkml.kernel.org/r/20230519101840.v5.6.I4e47cbfa1bb2ebbcdb5ca16817aa2887f15dc82c@changeid
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Chen-Yu Tsai <wens@xxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Colin Cross <ccross@xxxxxxxxxxx>
Cc: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Masayoshi Mizuma <msys.mizuma@xxxxxxxxx>
Cc: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Pingfan Liu <kernelfans@xxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: "Ravi V. Shankar" <ravi.v.shankar@xxxxxxxxx>
Cc: Ricardo Neri <ricardo.neri@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Cc: Sumit Garg <sumit.garg@xxxxxxxxxx>
Cc: Tzung-Bi Shih <tzungbi@xxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/nmi.h | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
--- a/include/linux/nmi.h~watchdog-hardlockup-add-comments-to-touch_nmi_watchdog
+++ a/include/linux/nmi.h
@@ -125,15 +125,30 @@ void watchdog_nmi_disable(unsigned int c
void lockup_detector_reconfigure(void);
/**
- * touch_nmi_watchdog - restart NMI watchdog timeout.
+ * touch_nmi_watchdog - manually pet the hardlockup watchdog.
*
- * If the architecture supports the NMI watchdog, touch_nmi_watchdog()
- * may be used to reset the timeout - for code which intentionally
- * disables interrupts for a long time. This call is stateless.
+ * If we support detecting hardlockups, touch_nmi_watchdog() may be
+ * used to pet the watchdog (reset the timeout) - for code which
+ * intentionally disables interrupts for a long time. This call is stateless.
+ *
+ * Though this function has "nmi" in the name, the hardlockup watchdog might
+ * not be backed by NMIs. This function will likely be renamed to
+ * touch_hardlockup_watchdog() in the future.
*/
static inline void touch_nmi_watchdog(void)
{
+ /*
+ * Pass on to the hardlockup detector selected via CONFIG_. Note that
+ * the hardlockup detector may not be arch-specific nor using NMIs
+ * and the arch_touch_nmi_watchdog() function will likely be renamed
+ * in the future.
+ */
arch_touch_nmi_watchdog();
+
+ /*
+ * Touching the hardlock detector implcitily pets the
+ * softlockup detector too
+ */
touch_softlockup_watchdog();
}
_
Patches currently in -mm which might be from dianders@xxxxxxxxxxxx are
migrate_pages-avoid-blocking-for-io-in-migrate_sync_light.patch
watchdog-perf-define-dummy-watchdog_update_hrtimer_threshold-on-correct-config.patch
watchdog-perf-more-properly-prevent-false-positives-with-turbo-modes.patch
watchdog-hardlockup-add-comments-to-touch_nmi_watchdog.patch
watchdog-perf-rename-watchdog_hldc-to-watchdog_perfc.patch
watchdog-hardlockup-move-perf-hardlockup-checking-panic-to-common-watchdogc.patch
watchdog-hardlockup-style-changes-to-watchdog_hardlockup_check-is_hardlockup.patch
watchdog-hardlockup-add-a-cpu-param-to-watchdog_hardlockup_check.patch
watchdog-hardlockup-move-perf-hardlockup-watchdog-petting-to-watchdogc.patch
watchdog-hardlockup-rename-some-nmi-watchdog-constants-function.patch
watchdog-hardlockup-have-the-perf-hardlockup-use-__weak-functions-more-cleanly.patch
watchdog-hardlockup-detect-hard-lockups-using-secondary-buddy-cpus.patch
watchdog-perf-add-a-weak-function-for-an-arch-to-detect-if-perf-can-use-nmis.patch
arm64-enable-perf-events-based-hard-lockup-detector.patch
