diff options
Diffstat (limited to 'kernel/watchdog_perf.c')
| -rw-r--r-- | kernel/watchdog_perf.c | 58 |
1 files changed, 53 insertions, 5 deletions
diff --git a/kernel/watchdog_perf.c b/kernel/watchdog_perf.c index 8ea00c4a24..59c1d86a73 100644 --- a/kernel/watchdog_perf.c +++ b/kernel/watchdog_perf.c @@ -75,11 +75,15 @@ static bool watchdog_check_timestamp(void) __this_cpu_write(last_timestamp, now); return true; } -#else -static inline bool watchdog_check_timestamp(void) + +static void watchdog_init_timestamp(void) { - return true; + __this_cpu_write(nmi_rearmed, 0); + __this_cpu_write(last_timestamp, ktime_get_mono_fast_ns()); } +#else +static inline bool watchdog_check_timestamp(void) { return true; } +static inline void watchdog_init_timestamp(void) { } #endif static struct perf_event_attr wd_hw_attr = { @@ -90,6 +94,14 @@ static struct perf_event_attr wd_hw_attr = { .disabled = 1, }; +static struct perf_event_attr fallback_wd_hw_attr = { + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_CPU_CYCLES, + .size = sizeof(struct perf_event_attr), + .pinned = 1, + .disabled = 1, +}; + /* Callback function for perf event subsystem */ static void watchdog_overflow_callback(struct perf_event *event, struct perf_sample_data *data, @@ -123,6 +135,13 @@ static int hardlockup_detector_event_create(void) evt = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL); if (IS_ERR(evt)) { + wd_attr = &fallback_wd_hw_attr; + wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh); + evt = perf_event_create_kernel_counter(wd_attr, cpu, NULL, + watchdog_overflow_callback, NULL); + } + + if (IS_ERR(evt)) { pr_debug("Perf event create on CPU %d failed with %ld\n", cpu, PTR_ERR(evt)); return PTR_ERR(evt); @@ -133,7 +152,6 @@ static int hardlockup_detector_event_create(void) /** * watchdog_hardlockup_enable - Enable the local event - * * @cpu: The CPU to enable hard lockup on. */ void watchdog_hardlockup_enable(unsigned int cpu) @@ -147,12 +165,12 @@ void watchdog_hardlockup_enable(unsigned int cpu) if (!atomic_fetch_inc(&watchdog_cpus)) pr_info("Enabled. Permanently consumes one hw-PMU counter.\n"); + watchdog_init_timestamp(); perf_event_enable(this_cpu_read(watchdog_ev)); } /** * watchdog_hardlockup_disable - Disable the local event - * * @cpu: The CPU to enable hard lockup on. */ void watchdog_hardlockup_disable(unsigned int cpu) @@ -259,3 +277,33 @@ int __init watchdog_hardlockup_probe(void) } return ret; } + +/** + * hardlockup_config_perf_event - Overwrite config of wd_hw_attr. + * @str: number which identifies the raw perf event to use + */ +void __init hardlockup_config_perf_event(const char *str) +{ + u64 config; + char buf[24]; + char *comma = strchr(str, ','); + + if (!comma) { + if (kstrtoull(str, 16, &config)) + return; + } else { + unsigned int len = comma - str; + + if (len >= sizeof(buf)) + return; + + if (strscpy(buf, str, sizeof(buf)) < 0) + return; + buf[len] = 0; + if (kstrtoull(buf, 16, &config)) + return; + } + + wd_hw_attr.type = PERF_TYPE_RAW; + wd_hw_attr.config = config; +} |