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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2013-04-20 15:58:34 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2013-04-22 19:59:39 +0200 |
| commit | 026249ef100b5384b6c74c360db46728e98354da (patch) | |
| tree | 7584442e88944643f10975956afd5ab151908908 | |
| parent | 12351ef8f9f2226636b00324d841d9c5069d80bc (diff) | |
| download | linux-stable-026249ef100b5384b6c74c360db46728e98354da.tar.gz linux-stable-026249ef100b5384b6c74c360db46728e98354da.tar.bz2 linux-stable-026249ef100b5384b6c74c360db46728e98354da.zip | |
perf: New helper to prevent full dynticks CPUs from stopping tick
Provide a new helper that help full dynticks CPUs to prevent
from stopping their tick in case there are events in the local
rotation list.
This way we make sure that perf_event_task_tick() is serviced
on demand.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
| -rw-r--r-- | include/linux/perf_event.h | 6 | ||||
| -rw-r--r-- | kernel/events/core.c | 10 |
2 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index e47ee462c2f2..0140830225e2 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -799,6 +799,12 @@ static inline int __perf_event_disable(void *info) { return -1; } static inline void perf_event_task_tick(void) { } #endif +#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_NO_HZ_FULL) +extern bool perf_event_can_stop_tick(void); +#else +static inline bool perf_event_can_stop_tick(void) { return true; } +#endif + #define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x)) /* diff --git a/kernel/events/core.c b/kernel/events/core.c index 75b58bb75b32..ddb993b52190 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2560,6 +2560,16 @@ done: list_del_init(&cpuctx->rotation_list); } +#ifdef CONFIG_NO_HZ_FULL +bool perf_event_can_stop_tick(void) +{ + if (list_empty(&__get_cpu_var(rotation_list))) + return true; + else + return false; +} +#endif + void perf_event_task_tick(void) { struct list_head *head = &__get_cpu_var(rotation_list); |