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| author | Thomas Gleixner <tglx@linutronix.de> | 2017-09-12 21:37:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-14 11:41:07 +0200 |
| commit | 6592ad2fcc8f15b4f99b36c1db7d9f65510c203b (patch) | |
| tree | bb6e84eec793718c24aba5f19a28e5473f751f43 /kernel | |
| parent | watchdog/sysctl: Clean up sysctl variable name space (diff) | |
| download | linux-6592ad2fcc8f15b4f99b36c1db7d9f65510c203b.tar.xz linux-6592ad2fcc8f15b4f99b36c1db7d9f65510c203b.zip | |
watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage
Both the perf reconfiguration and the powerpc watchdog_nmi_reconfigure()
need to be done in two steps.
1) Stop all NMIs
2) Read the new parameters and start NMIs
Right now watchdog_nmi_reconfigure() is a combination of both. To allow a
clean reconfiguration add a 'run' argument and split the functionality in
powerpc.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170912194147.862865570@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/watchdog.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index baae9fc95031..5693afd2b8ea 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -112,17 +112,25 @@ void __weak watchdog_nmi_disable(unsigned int cpu) hardlockup_detector_perf_disable(); } -/* - * watchdog_nmi_reconfigure can be implemented to be notified after any - * watchdog configuration change. The arch hardlockup watchdog should - * respond to the following variables: +/** + * watchdog_nmi_reconfigure - Optional function to reconfigure NMI watchdogs + * @run: If false stop the watchdogs on all enabled CPUs + * If true start the watchdogs on all enabled CPUs + * + * The core call order is: + * watchdog_nmi_reconfigure(false); + * update_variables(); + * watchdog_nmi_reconfigure(true); + * + * The second call which starts the watchdogs again guarantees that the + * following variables are stable across the call. * - watchdog_enabled * - watchdog_thresh * - watchdog_cpumask - * - sysctl_hardlockup_all_cpu_backtrace - * - hardlockup_panic + * + * After the call the variables can be changed again. */ -void __weak watchdog_nmi_reconfigure(void) { } +void __weak watchdog_nmi_reconfigure(bool run) { } #ifdef CONFIG_SOFTLOCKUP_DETECTOR @@ -515,10 +523,12 @@ static void softlockup_unpark_threads(void) static void softlockup_reconfigure_threads(bool enabled) { + watchdog_nmi_reconfigure(false); softlockup_park_all_threads(); set_sample_period(); if (enabled) softlockup_unpark_threads(); + watchdog_nmi_reconfigure(true); } /* @@ -559,7 +569,11 @@ static inline void watchdog_unpark_threads(void) { } static inline int watchdog_enable_all_cpus(void) { return 0; } static inline void watchdog_disable_all_cpus(void) { } static inline void softlockup_init_threads(void) { } -static inline void softlockup_reconfigure_threads(bool enabled) { } +static void softlockup_reconfigure_threads(bool enabled) +{ + watchdog_nmi_reconfigure(false); + watchdog_nmi_reconfigure(true); +} #endif /* !CONFIG_SOFTLOCKUP_DETECTOR */ static void __lockup_detector_cleanup(void) @@ -599,7 +613,6 @@ static void proc_watchdog_update(void) /* Remove impossible cpus to keep sysctl output clean. */ cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask); softlockup_reconfigure_threads(watchdog_enabled && watchdog_thresh); - watchdog_nmi_reconfigure(); } /* |