From 5622f295b53fb60dbf9bed3e2c89d182490a8b7f Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Tue, 15 Sep 2009 13:00:23 +0200 Subject: x86, perf_counter, bts: Optimize BTS overflow handling Draining the BTS buffer on a buffer overflow interrupt takes too long resulting in a kernel lockup when tracing the kernel. Restructure perf_counter sampling into sample creation and sample output. Prepare a single reference sample for BTS sampling and update the from and to address fields when draining the BTS buffer. Drain the entire BTS buffer between a single perf_output_begin() / perf_output_end() pair. Signed-off-by: Markus Metzger Signed-off-by: Peter Zijlstra LKML-Reference: <20090915130023.A16204@sedona.ch.intel.com> Signed-off-by: Ingo Molnar --- include/linux/perf_counter.h | 68 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 64 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 6c1ef72ea501..c7375f97aa19 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -691,6 +691,17 @@ struct perf_cpu_context { int recursion[4]; }; +struct perf_output_handle { + struct perf_counter *counter; + struct perf_mmap_data *data; + unsigned long head; + unsigned long offset; + int nmi; + int sample; + int locked; + unsigned long flags; +}; + #ifdef CONFIG_PERF_COUNTERS /* @@ -722,16 +733,38 @@ extern int hw_perf_group_sched_in(struct perf_counter *group_leader, extern void perf_counter_update_userpage(struct perf_counter *counter); struct perf_sample_data { - struct pt_regs *regs; + u64 type; + + u64 ip; + struct { + u32 pid; + u32 tid; + } tid_entry; + u64 time; u64 addr; + u64 id; + u64 stream_id; + struct { + u32 cpu; + u32 reserved; + } cpu_entry; u64 period; + struct perf_callchain_entry *callchain; struct perf_raw_record *raw; }; +extern void perf_output_sample(struct perf_output_handle *handle, + struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_counter *counter); +extern void perf_prepare_sample(struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_counter *counter, + struct pt_regs *regs); + extern int perf_counter_overflow(struct perf_counter *counter, int nmi, - struct perf_sample_data *data); -extern void perf_counter_output(struct perf_counter *counter, int nmi, - struct perf_sample_data *data); + struct perf_sample_data *data, + struct pt_regs *regs); /* * Return 1 for a software counter, 0 for a hardware counter @@ -781,6 +814,12 @@ extern void perf_tpcounter_event(int event_id, u64 addr, u64 count, #define perf_instruction_pointer(regs) instruction_pointer(regs) #endif +extern int perf_output_begin(struct perf_output_handle *handle, + struct perf_counter *counter, unsigned int size, + int nmi, int sample); +extern void perf_output_end(struct perf_output_handle *handle); +extern void perf_output_copy(struct perf_output_handle *handle, + const void *buf, unsigned int len); #else static inline void perf_counter_task_sched_in(struct task_struct *task, int cpu) { } @@ -807,7 +846,28 @@ static inline void perf_counter_mmap(struct vm_area_struct *vma) { } static inline void perf_counter_comm(struct task_struct *tsk) { } static inline void perf_counter_fork(struct task_struct *tsk) { } static inline void perf_counter_init(void) { } + +static inline int +perf_output_begin(struct perf_output_handle *handle, struct perf_counter *c, + unsigned int size, int nmi, int sample) { } +static inline void perf_output_end(struct perf_output_handle *handle) { } +static inline void +perf_output_copy(struct perf_output_handle *handle, + const void *buf, unsigned int len) { } +static inline void +perf_output_sample(struct perf_output_handle *handle, + struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_counter *counter) { } +static inline void +perf_prepare_sample(struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_counter *counter, + struct pt_regs *regs) { } #endif +#define perf_output_put(handle, x) \ + perf_output_copy((handle), &(x), sizeof(x)) + #endif /* __KERNEL__ */ #endif /* _LINUX_PERF_COUNTER_H */ -- cgit v1.2.3