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Groups > linux.kernel > #1732193
| From | tip-bot for Thomas Gleixner <tipbot@zytor.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [tip:core/urgent] watchdog/hardlockup/perf: Implement init time perf validation |
| Date | 2017-09-14 13:00 +0200 |
| Message-ID | <upA2d-3WF-1@gated-at.bofh.it> (permalink) |
| References | <uoZvJ-5zK-47@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Commit-ID: 178b9f7a36d2c74a38274b66dd89f53611298a19
Gitweb: http://git.kernel.org/tip/178b9f7a36d2c74a38274b66dd89f53611298a19
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 12 Sep 2017 21:37:18 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 14 Sep 2017 11:41:08 +0200
watchdog/hardlockup/perf: Implement init time perf validation
The watchdog tries to create perf events even after it figured out that
perf is not functional or the requested event is not supported.
That's braindead as this can be done once at init time and if not supported
the NMI watchdog can be turned off unconditonally.
Implement the perf hardlockup detector functionality for that. This creates
a new event create function, which will replace the unholy mess of the
existing one in later patches.
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/20170912194148.019090547@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/nmi.h | 8 ++++++--
kernel/watchdog_hld.c | 37 +++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index eee255b..72c62a8 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -93,14 +93,18 @@ 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_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_cleanup(void) { }
-#if !defined(CONFIG_HAVE_NMI_WATCHDOG)
+# if !defined(CONFIG_HAVE_NMI_WATCHDOG)
+static inline int hardlockup_detector_perf_init(void) { return -ENODEV; }
static inline void arch_touch_nmi_watchdog(void) {}
-#endif
+# else
+static inline int hardlockup_detector_perf_init(void) { return 0; }
+# endif
#endif
void watchdog_nmi_reconfigure(bool run);
diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
index 0aa191e..f7e752e 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;
+}
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[patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[patch V2 14/29] lockup_detector: Split out cpumask write function Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/core: Split out cpumask write function tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 05/29] lockup_detector: Remove broken suspend/resume interfaces Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/core: Remove broken suspend/resume interfaces tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 16/29] lockup_detector: Create new thread handling infrastructure Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/core: Create new thread handling infrastructure tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 01/29] hardlockup_detector: Provide interface to stop/restart perf events Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/hardlockup: Provide interface to stop/restart perf events tip-bot for Peter Zijlstra <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 26/29] lockup_detector/perf: Implement CPU enable replacement Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Implement CPU enable replacement tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 06/29] lockup_detector: Rework cpu hotplug locking Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Rework CPU hotplug locking tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 28/29] lockup_detector/perf: Simplify deferred event destroy Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Simplify deferred event destroy tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 04/29] parisc: Use lockup_detector_stop() Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
Re: [patch V2 04/29] parisc: Use lockup_detector_stop() Helge Deller <deller@gmx.de> - 2017-09-14 11:10 +0200
Re: [patch V2 04/29] parisc: Use lockup_detector_stop() Don Zickus <dzickus@redhat.com> - 2017-09-14 15:50 +0200
[tip:core/urgent] parisc, watchdog/core: Use lockup_detector_stop() tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 17/29] lockup_detector: Get rid of the thread teardown/setup dance Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Get rid of the thread teardown/setup dance tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 03/29] lockup_detector: Provide interface to stop from poweroff() Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Provide interface to stop from poweroff() tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 10/29] lockup_detector/perf: Prevent cpu hotplug deadlock Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Prevent CPU hotplug deadlock tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 13/29] lockup_detector: Cleanup the ifdef maze Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Clean up the #ifdef maze tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 29/29] lockup_detector: Cleanup hotplug locking mess Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup: Clean up hotplug locking mess tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 09/29] lockup_detector/perf: Remove broken self disable on failure Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Remove broken self disable on failure tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 08/29] lockup_detector: Mark hardlockup_detector_disable() __init Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Mark hardlockup_detector_disable() __init tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 18/29] lockup_detector: Further simplify sysctl handling Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Further simplify sysctl handling tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 12/29] lockup_detector: Cleanup stub functions Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Clean up stub functions tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 15/29] smpboot/threads: Avoid runtime allocation Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] smpboot/threads, watchdog/core: Avoid runtime allocation tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 20/29] lockup_detector/sysctl: Get rid of the ifdeffery Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/sysctl: Get rid of the #ifdeffery tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 27/29] lockup_detector: Use new perf CPU enable mechanism Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Use new perf CPU enable mechanism tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 24/29] lockup_detector/perf: Implement init time perf validation Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Implement init time perf validation tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 19/29] lockup_detector: Cleanup header mess Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Clean up header mess tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 22/29] lockup_detector: Make watchdog_nmi_reconfigure() two stage Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 25/29] lockup_detector: Implement init time detection of perf Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
Re: [patch V2 25/29] lockup_detector: Implement init time detection of perf Don Zickus <dzickus@redhat.com> - 2017-09-13 20:10 +0200
Re: [patch V2 25/29] lockup_detector: Implement init time detection of perf Thomas Gleixner <tglx@linutronix.de> - 2017-09-13 20:10 +0200
Re: [patch V2 25/29] lockup_detector: Implement init time detection of perf Ingo Molnar <mingo@kernel.org> - 2017-09-14 07:30 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Implement init time detection of perf tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 23/29] lockup_detector: Get rid of the racy update loop Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Get rid of the racy update loop tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
Re: [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Don Zickus <dzickus@redhat.com> - 2017-09-13 20:10 +0200
Re: [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Ingo Molnar <mingo@kernel.org> - 2017-09-14 07:30 +0200
Re: [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Thomas Gleixner <tglx@linutronix.de> - 2017-09-14 10:20 +0200
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