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-rw-r--r--include/linux/nmi.h2
-rw-r--r--kernel/watchdog_perf.c22
2 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index e78fa535f61d..cf3c6ab408aa 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -103,10 +103,12 @@ void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs);
extern void hardlockup_detector_perf_stop(void);
extern void hardlockup_detector_perf_restart(void);
extern void hardlockup_config_perf_event(const char *str);
+extern void hardlockup_detector_perf_adjust_period(u64 period);
#else
static inline void hardlockup_detector_perf_stop(void) { }
static inline void hardlockup_detector_perf_restart(void) { }
static inline void hardlockup_config_perf_event(const char *str) { }
+static inline void hardlockup_detector_perf_adjust_period(u64 period) { }
#endif
void watchdog_hardlockup_stop(void);
diff --git a/kernel/watchdog_perf.c b/kernel/watchdog_perf.c
index 75af12ff774e..9c58f5b4381d 100644
--- a/kernel/watchdog_perf.c
+++ b/kernel/watchdog_perf.c
@@ -187,6 +187,28 @@ void watchdog_hardlockup_disable(unsigned int cpu)
}
/**
+ * hardlockup_detector_perf_adjust_period - Adjust the event period due
+ * to current cpu frequency change
+ * @period: The target period to be set
+ */
+void hardlockup_detector_perf_adjust_period(u64 period)
+{
+ struct perf_event *event = this_cpu_read(watchdog_ev);
+
+ if (!(watchdog_enabled & WATCHDOG_HARDLOCKUP_ENABLED))
+ return;
+
+ if (!event)
+ return;
+
+ if (event->attr.sample_period == period)
+ return;
+
+ if (perf_event_period(event, period))
+ pr_err("failed to change period to %llu\n", period);
+}
+
+/**
* hardlockup_detector_perf_stop - Globally stop watchdog events
*
* Special interface for x86 to handle the perf HT bug.