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-rw-r--r--kernel/watchdog_hld.c37
1 files changed, 37 insertions, 0 deletions
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;
+}