Commit d3b62ace authored by Douglas Anderson's avatar Douglas Anderson Committed by Andrew Morton
Browse files

watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called 

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: default avatarDouglas Anderson <dianders@chromium.org>
Suggested-by: default avatarPetr Mladek <pmladek@suse.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 05e7b558

include/linux/nmi.h

+2 −2
Original line number Diff line number Diff line
@@ -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



/**

kernel/watchdog.c

+7 −8
Original line number Diff line number Diff line
@@ -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))) {

kernel/watchdog_buddy.c

+1 −1
Original line number Diff line number Diff line
@@ -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;