diff options
| -rw-r--r-- | include/linux/nmi.h | 8 | ||||
| -rw-r--r-- | kernel/watchdog_hld.c | 37 |
2 files changed, 43 insertions, 2 deletions
diff --git a/include/linux/nmi.h b/include/linux/nmi.h index eee255bc0fd6..72c62a809e92 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -93,14 +93,18 @@ extern void hardlockup_detector_perf_stop(void); extern void hardlockup_detector_perf_restart(void); extern void hardlockup_detector_perf_disable(void); extern void hardlockup_detector_perf_cleanup(void); +extern int hardlockup_detector_perf_init(void); #else static inline void hardlockup_detector_perf_stop(void) { } static inline void hardlockup_detector_perf_restart(void) { } static inline void hardlockup_detector_perf_disable(void) { } static inline void hardlockup_detector_perf_cleanup(void) { } -#if !defined(CONFIG_HAVE_NMI_WATCHDOG) +# if !defined(CONFIG_HAVE_NMI_WATCHDOG) +static inline int hardlockup_detector_perf_init(void) { return -ENODEV; } static inline void arch_touch_nmi_watchdog(void) {} -#endif +# else +static inline int hardlockup_detector_perf_init(void) { return 0; } +# endif #endif void watchdog_nmi_reconfigure(bool run); diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 0aa191ee3d51..f7e752e6e9b4 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -238,6 +238,27 @@ out: return 0; } +static int hardlockup_detector_event_create(void) +{ + unsigned int cpu = smp_processor_id(); + struct perf_event_attr *wd_attr; + struct perf_event *evt; + + wd_attr = &wd_hw_attr; + wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh); + + /* Try to register using hardware perf events */ + evt = perf_event_create_kernel_counter(wd_attr, cpu, NULL, + watchdog_overflow_callback, NULL); + if (IS_ERR(evt)) { + pr_info("Perf event create on CPU %d failed with %ld\n", cpu, + PTR_ERR(evt)); + return PTR_ERR(evt); + } + this_cpu_write(watchdog_ev, evt); + return 0; +} + /** * hardlockup_detector_perf_disable - Disable the local event */ @@ -315,3 +336,19 @@ void __init hardlockup_detector_perf_restart(void) perf_event_enable(event); } } + +/** + * hardlockup_detector_perf_init - Probe whether NMI event is available at all + */ +int __init hardlockup_detector_perf_init(void) +{ + int ret = hardlockup_detector_event_create(); + + if (ret) { + pr_info("Perf NMI watchdog permanetely disabled\n"); + } else { + perf_event_release_kernel(this_cpu_read(watchdog_ev)); + this_cpu_write(watchdog_ev, NULL); + } + return ret; +} |