The patch titled
Subject: watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
has been added to the -mm mm-nonmm-unstable branch. Its filename is
watchdog-buddy-cleanup-how-watchdog_buddy_check_hardlockup-is-called.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/watchdog-buddy-cleanup-how-watchdog_buddy_check_hardlockup-is-called.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Douglas Anderson <dianders@xxxxxxxxxxxx>
Subject: watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
Date: Fri, 26 May 2023 18:41:36 -0700
In the patch ("watchdog/hardlockup: detect hard lockups using secondary
(buddy) CPUs"), we added a call from the common watchdog.c file into the
buddy. That call could be done more cleanly. Specifically:
1. If we move the call into watchdog_hardlockup_kick() then it keeps
watchdog_timer_fn() simpler.
2. We don't need to pass an "unsigned long" to the buddy for the timer
count. In the patch ("watchdog/hardlockup: add a "cpu" param to
watchdog_hardlockup_check()") the count was changed to "atomic_t"
which is backed by an int, so we should match types.
Link: https://lkml.kernel.org/r/20230526184139.6.I006c7d958a1ea5c4e1e4dc44a25596d9bb5fd3ba@changeid
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Suggested-by: Petr Mladek <pmladek@xxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/nmi.h | 4 ++--
kernel/watchdog.c | 15 +++++++--------
kernel/watchdog_buddy.c | 2 +-
3 files changed, 10 insertions(+), 11 deletions(-)
--- a/include/linux/nmi.h~watchdog-buddy-cleanup-how-watchdog_buddy_check_hardlockup-is-called
+++ a/include/linux/nmi.h
@@ -114,9 +114,9 @@ void watchdog_hardlockup_disable(unsigne
void lockup_detector_reconfigure(void);
#ifdef CONFIG_HARDLOCKUP_DETECTOR_BUDDY
-void watchdog_buddy_check_hardlockup(unsigned long hrtimer_interrupts);
+void watchdog_buddy_check_hardlockup(int hrtimer_interrupts);
#else
-static inline void watchdog_buddy_check_hardlockup(unsigned long hrtimer_interrupts) {}
+static inline void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) {}
#endif
/**
--- a/kernel/watchdog_buddy.c~watchdog-buddy-cleanup-how-watchdog_buddy_check_hardlockup-is-called
+++ a/kernel/watchdog_buddy.c
@@ -72,7 +72,7 @@ void watchdog_hardlockup_disable(unsigne
cpumask_clear_cpu(cpu, &watchdog_cpus);
}
-void watchdog_buddy_check_hardlockup(unsigned long hrtimer_interrupts)
+void watchdog_buddy_check_hardlockup(int hrtimer_interrupts)
{
unsigned int next_cpu;
--- a/kernel/watchdog.c~watchdog-buddy-cleanup-how-watchdog_buddy_check_hardlockup-is-called
+++ a/kernel/watchdog.c
@@ -131,9 +131,12 @@ static bool is_hardlockup(unsigned int c
return false;
}
-static unsigned long watchdog_hardlockup_kick(void)
+static void watchdog_hardlockup_kick(void)
{
- return atomic_inc_return(this_cpu_ptr(&hrtimer_interrupts));
+ int new_interrupts;
+
+ new_interrupts = atomic_inc_return(this_cpu_ptr(&hrtimer_interrupts));
+ watchdog_buddy_check_hardlockup(new_interrupts);
}
void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs)
@@ -195,7 +198,7 @@ void watchdog_hardlockup_check(unsigned
#else /* CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER */
-static inline unsigned long watchdog_hardlockup_kick(void) { return 0; }
+static inline void watchdog_hardlockup_kick(void) { }
#endif /* !CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER */
@@ -449,15 +452,11 @@ static enum hrtimer_restart watchdog_tim
struct pt_regs *regs = get_irq_regs();
int duration;
int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace;
- unsigned long hrtimer_interrupts;
if (!watchdog_enabled)
return HRTIMER_NORESTART;
- hrtimer_interrupts = watchdog_hardlockup_kick();
-
- /* test for hardlockups */
- watchdog_buddy_check_hardlockup(hrtimer_interrupts);
+ watchdog_hardlockup_kick();
/* kick the softlockup detector */
if (completion_done(this_cpu_ptr(&softlockup_completion))) {
_
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
arm64-enable-perf-events-based-hard-lockup-detector-fix.patch
watchdog-hardlockup-keep-kernelnmi_watchdog-sysctl-as-0444-if-probe-fails.patch
watchdog-hardlockup-have_nmi_watchdog-must-implement-watchdog_hardlockup_probe.patch
watchdog-hardlockup-dont-use-raw_cpu_ptr-in-watchdog_hardlockup_kick.patch
watchdog-hardlockup-in-watchdog_hardlockup_check-use-cpumask_copy.patch
watchdog-hardlockup-remove-softlockup-comment-in-touch_nmi_watchdog.patch
watchdog-buddy-cleanup-how-watchdog_buddy_check_hardlockup-is-called.patch
watchdog-buddy-dont-copy-the-cpumask-in-watchdog_next_cpu.patch
watchdog-buddy-simplify-the-dependency-for-hardlockup_detector_prefer_buddy.patch
watchdog-hardlockup-move-smp-barriers-from-common-code-to-buddy-code.patch
watchdog-hardlockup-rename-have_hardlockup_detector_non_arch-to-_perf_or_buddy.patch
