watchdog/hardlockup/perf: Implement CPU enable replacement

watchdog_nmi_enable() is an unparseable mess, Provide a clean perf specific
implementation, which will be used when the existing setup/teardown mess is
replaced.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194148.180215498@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
index f7e752e6e9b4..99a3f22e48cc 100644
--- a/kernel/watchdog_hld.c
+++ b/kernel/watchdog_hld.c
@@ -260,6 +260,17 @@ static int hardlockup_detector_event_create(void)
 }
 
 /**
+ * hardlockup_detector_perf_enable - Enable the local event
+ */
+void hardlockup_detector_perf_enable(void)
+{
+        if (hardlockup_detector_event_create())
+                return;
+
+        perf_event_enable(this_cpu_read(watchdog_ev));
+}
+
+/**
  * hardlockup_detector_perf_disable - Disable the local event
  */
 void hardlockup_detector_perf_disable(void)