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| author | Thomas Gleixner <tglx@linutronix.de> | 2008-12-09 21:43:39 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-11 15:45:45 +0100 |
| commit | 4ac13294e44664bb7edf4daf52edb71e7c6bbe84 (patch) | |
| tree | accb533350a655e39a8ab846abc37018b2f87ccf /include/linux/perf_counter.h | |
| parent | 43874d238d5f208854a73c3225ca2a22833eec8b (diff) | |
| download | linux-stable-4ac13294e44664bb7edf4daf52edb71e7c6bbe84.tar.gz linux-stable-4ac13294e44664bb7edf4daf52edb71e7c6bbe84.tar.bz2 linux-stable-4ac13294e44664bb7edf4daf52edb71e7c6bbe84.zip | |
perf counters: protect them against CSTATE transitions
Impact: fix rare lost events problem
There are CPUs whose performance counters misbehave on CSTATE transitions,
so provide a way to just disable/enable them around deep idle methods.
(hw_perf_enable_all() is cheap on x86.)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/perf_counter.h')
| -rw-r--r-- | include/linux/perf_counter.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 22c4469abf44..5031b5614f25 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -156,6 +156,8 @@ extern void perf_counter_task_tick(struct task_struct *task, int cpu); extern void perf_counter_init_task(struct task_struct *task); extern void perf_counter_notify(struct pt_regs *regs); extern void perf_counter_print_debug(void); +extern void hw_perf_restore_ctrl(u64 ctrl); +extern u64 hw_perf_disable_all(void); #else static inline void perf_counter_task_sched_in(struct task_struct *task, int cpu) { } @@ -166,6 +168,8 @@ perf_counter_task_tick(struct task_struct *task, int cpu) { } static inline void perf_counter_init_task(struct task_struct *task) { } static inline void perf_counter_notify(struct pt_regs *regs) { } static inline void perf_counter_print_debug(void) { } +static inline void hw_perf_restore_ctrl(u64 ctrl) { } +static inline u64 hw_perf_disable_all(void) { return 0; } #endif #endif /* _LINUX_PERF_COUNTER_H */ |