[patch V2 26/29] lockup_detector/perf: Implement CPU enable replacement

Thomas Gleixner
2017-09-12T19:51:20Z

[-- Attachment #1: lockup_detectorperf_Implement_CPU_enable_replacement.patch --]
[-- Type: text/plain, Size: 2056 bytes --]

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>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20170831073055.081402493@linutronix.de

---
include/linux/nmi.h | 2 ++
kernel/watchdog_hld.c | 11 +++++++++++
2 files changed, 13 insertions(+)

--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -92,12 +92,14 @@ extern void arch_touch_nmi_watchdog(void
extern void hardlockup_detector_perf_stop(void);
extern void hardlockup_detector_perf_restart(void);
extern void hardlockup_detector_perf_disable(void);
+extern void hardlockup_detector_perf_enable(void);
extern void hardlockup_detector_perf_cleanup(void);
extern int hardlockup_detector_perf_init(void);
#else
static inline void hardlockup_detector_perf_stop(void) { }
static inline void hardlockup_detector_perf_restart(void) { }
static inline void hardlockup_detector_perf_disable(void) { }
+static inline void hardlockup_detector_perf_enable(void) { }
static inline void hardlockup_detector_perf_cleanup(void) { }
# if !defined(CONFIG_HAVE_NMI_WATCHDOG)
static inline int hardlockup_detector_perf_init(void) { return -ENODEV; }
--- a/kernel/watchdog_hld.c
+++ b/kernel/watchdog_hld.c
@@ -260,6 +260,17 @@ static int hardlockup_detector_event_cre
}

/**
+ * 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)