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-rw-r--r--include/linux/nmi.h4
-rw-r--r--kernel/watchdog_hld.c41
2 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index a36abe2da13e..b24d4a58674a 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -75,7 +75,11 @@ static inline void hardlockup_detector_disable(void) {}
#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
extern void arch_touch_nmi_watchdog(void);
+extern void hardlockup_detector_perf_stop(void);
+extern void hardlockup_detector_perf_restart(void);
#else
+static inline void hardlockup_detector_perf_stop(void) { }
+static inline void hardlockup_detector_perf_restart(void) { }
#if !defined(CONFIG_HAVE_NMI_WATCHDOG)
static inline void arch_touch_nmi_watchdog(void) {}
#endif
diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
index 3a09ea1b1d3d..c9586ebc2e98 100644
--- a/kernel/watchdog_hld.c
+++ b/kernel/watchdog_hld.c
@@ -261,3 +261,44 @@ void watchdog_nmi_disable(unsigned int cpu)
firstcpu_err = 0;
}
}
+
+/**
+ * hardlockup_detector_perf_stop - Globally stop watchdog events
+ *
+ * Special interface for x86 to handle the perf HT bug.
+ */
+void __init hardlockup_detector_perf_stop(void)
+{
+ int cpu;
+
+ lockdep_assert_cpus_held();
+
+ for_each_online_cpu(cpu) {
+ struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+ if (event)
+ perf_event_disable(event);
+ }
+}
+
+/**
+ * hardlockup_detector_perf_restart - Globally restart watchdog events
+ *
+ * Special interface for x86 to handle the perf HT bug.
+ */
+void __init hardlockup_detector_perf_restart(void)
+{
+ int cpu;
+
+ lockdep_assert_cpus_held();
+
+ if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+ return;
+
+ for_each_online_cpu(cpu) {
+ struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+ if (event)
+ perf_event_enable(event);
+ }
+}