diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel.c | 4 | ||||
| -rw-r--r-- | include/linux/nmi.h | 8 | ||||
| -rw-r--r-- | kernel/watchdog.c | 26 |
3 files changed, 28 insertions, 10 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 144ab91951a7..cd9b6d0b10bf 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -3627,7 +3627,7 @@ static __init int fixup_ht_bug(void) return 0; } - if (watchdog_suspend() != 0) { + if (lockup_detector_suspend() != 0) { pr_debug("failed to disable PMU erratum BJ122, BV98, HSD29 workaround\n"); return 0; } @@ -3638,7 +3638,7 @@ static __init int fixup_ht_bug(void) x86_pmu.commit_scheduling = NULL; x86_pmu.stop_scheduling = NULL; - watchdog_resume(); + lockup_detector_resume(); get_online_cpus(); diff --git a/include/linux/nmi.h b/include/linux/nmi.h index e5afe8bae202..a91adf6e02f2 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -78,15 +78,15 @@ extern int proc_watchdog_thresh(struct ctl_table *, int , void __user *, size_t *, loff_t *); extern int proc_watchdog_cpumask(struct ctl_table *, int, void __user *, size_t *, loff_t *); -extern int watchdog_suspend(void); -extern void watchdog_resume(void); +extern int lockup_detector_suspend(void); +extern void lockup_detector_resume(void); #else -static inline int watchdog_suspend(void) +static inline int lockup_detector_suspend(void) { return 0; } -static inline void watchdog_resume(void) +static inline void lockup_detector_resume(void) { } #endif diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 69666f4b8e8f..64ed1c37bd1f 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -67,8 +67,26 @@ unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask); #define for_each_watchdog_cpu(cpu) \ for_each_cpu_and((cpu), cpu_online_mask, &watchdog_cpumask) -static int __read_mostly watchdog_suspended; +/* + * The 'watchdog_running' variable is set to 1 when the watchdog threads + * are registered/started and is set to 0 when the watchdog threads are + * unregistered/stopped, so it is an indicator whether the threads exist. + */ static int __read_mostly watchdog_running; +/* + * If a subsystem has a need to deactivate the watchdog temporarily, it + * can use the suspend/resume interface to achieve this. The content of + * the 'watchdog_suspended' variable reflects this state. Existing threads + * are parked/unparked by the lockup_detector_{suspend|resume} functions + * (see comment blocks pertaining to those functions for further details). + * + * 'watchdog_suspended' also prevents threads from being registered/started + * or unregistered/stopped via parameters in /proc/sys/kernel, so the state + * of 'watchdog_running' cannot change while the watchdog is deactivated + * temporarily (see related code in 'proc' handlers). + */ +static int __read_mostly watchdog_suspended; + static u64 __read_mostly sample_period; static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); @@ -669,7 +687,7 @@ static void watchdog_unpark_threads(void) /* * Suspend the hard and soft lockup detector by parking the watchdog threads. */ -int watchdog_suspend(void) +int lockup_detector_suspend(void) { int ret = 0; @@ -679,7 +697,7 @@ int watchdog_suspend(void) * the 'watchdog_suspended' variable). If the watchdog threads are * running, the first caller takes care that they will be parked. * The state of 'watchdog_running' cannot change while a suspend - * request is active (see related changes in 'proc' handlers). + * request is active (see related code in 'proc' handlers). */ if (watchdog_running && !watchdog_suspended) ret = watchdog_park_threads(); @@ -695,7 +713,7 @@ int watchdog_suspend(void) /* * Resume the hard and soft lockup detector by unparking the watchdog threads. */ -void watchdog_resume(void) +void lockup_detector_resume(void) { mutex_lock(&watchdog_proc_mutex); |