diff mbox series

[06/10] watchdog/buddy: Cleanup how watchdog_buddy_check_hardlockup() is called

Message ID 20230526184139.6.I006c7d958a1ea5c4e1e4dc44a25596d9bb5fd3ba@changeid
State New
Headers
Series watchdog: Cleanup / fixes after buddy series v5 reviews |

Commit Message

Doug Anderson May 27, 2023, 1:41 a.m. UTC 
  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.

Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 include/linux/nmi.h     |  4 ++--
 kernel/watchdog.c       | 15 +++++++--------
 kernel/watchdog_buddy.c |  2 +-
 3 files changed, 10 insertions(+), 11 deletions(-)

Comments

Petr Mladek May 30, 2023, 2:56 p.m. UTC | #1 
On Fri 2023-05-26 18:41:36, Douglas Anderson wrote:
> 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.
> 
> Suggested-by: Petr Mladek <pmladek@suse.com>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>


The change looks fine:

Reviewed-by: Petr Mladek <pmladek@suse.com>

That said, I would prefer to squash it into the patch ("watchdog/hardlockup:
detect hard lockups using secondary (buddy) CPUs"). It would remove
some back and forth churn in the git history. But it is up to Andrew.

Best Regards,
Petr
diff mbox series

Patch

diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 6c6a5ce77c66..43893e5f858a 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -114,9 +114,9 @@  void watchdog_hardlockup_disable(unsigned int cpu);
 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
 
 /**
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 85f4839b6faf..6cc46b8e3d07 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -131,9 +131,12 @@  static bool is_hardlockup(unsigned int cpu)
 	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 int cpu, struct pt_regs *regs)
 
 #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_timer_fn(struct hrtimer *hrtimer)
 	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))) {
diff --git a/kernel/watchdog_buddy.c b/kernel/watchdog_buddy.c
index fee45af2e5bd..3ffc5f2ede5a 100644
--- a/kernel/watchdog_buddy.c
+++ b/kernel/watchdog_buddy.c
@@ -72,7 +72,7 @@  void watchdog_hardlockup_disable(unsigned int cpu)
 	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;