diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2008-12-04 20:12:29 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-12-08 15:47:03 +0100 |
commit | 0793a61d4df8daeac6492dbf8d2f3e5713caae5e (patch) | |
tree | cc9603eb8daffeb7ace521c42a6a44db164ac551 /include/linux/perf_counter.h | |
parent | b5aa97e83bcc31a96374d18f5452d53909a16c90 (diff) | |
download | linux-stable-0793a61d4df8daeac6492dbf8d2f3e5713caae5e.tar.gz linux-stable-0793a61d4df8daeac6492dbf8d2f3e5713caae5e.tar.bz2 linux-stable-0793a61d4df8daeac6492dbf8d2f3e5713caae5e.zip |
performance counters: core code
Implement the core kernel bits of Performance Counters subsystem.
The Linux Performance Counter subsystem provides an abstraction of
performance counter hardware capabilities. It provides per task and per
CPU counters, and it provides event capabilities on top of those.
Performance counters are accessed via special file descriptors.
There's one file descriptor per virtual counter used.
The special file descriptor is opened via the perf_counter_open()
system call:
int
perf_counter_open(u32 hw_event_type,
u32 hw_event_period,
u32 record_type,
pid_t pid,
int cpu);
The syscall returns the new fd. The fd can be used via the normal
VFS system calls: read() can be used to read the counter, fcntl()
can be used to set the blocking mode, etc.
Multiple counters can be kept open at a time, and the counters
can be poll()ed.
See more details in Documentation/perf-counters.txt.
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 | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h new file mode 100644 index 000000000000..22c4469abf44 --- /dev/null +++ b/include/linux/perf_counter.h @@ -0,0 +1,171 @@ +/* + * Performance counters: + * + * Copyright(C) 2008, Thomas Gleixner <tglx@linutronix.de> + * Copyright(C) 2008, Red Hat, Inc., Ingo Molnar + * + * Data type definitions, declarations, prototypes. + * + * Started by: Thomas Gleixner and Ingo Molnar + * + * For licencing details see kernel-base/COPYING + */ +#ifndef _LINUX_PERF_COUNTER_H +#define _LINUX_PERF_COUNTER_H + +#include <asm/atomic.h> + +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/rculist.h> +#include <linux/rcupdate.h> +#include <linux/spinlock.h> + +struct task_struct; + +/* + * Generalized hardware event types, used by the hw_event_type parameter + * of the sys_perf_counter_open() syscall: + */ +enum hw_event_types { + PERF_COUNT_CYCLES, + PERF_COUNT_INSTRUCTIONS, + PERF_COUNT_CACHE_REFERENCES, + PERF_COUNT_CACHE_MISSES, + PERF_COUNT_BRANCH_INSTRUCTIONS, + PERF_COUNT_BRANCH_MISSES, + /* + * If this bit is set in the type, then trigger NMI sampling: + */ + PERF_COUNT_NMI = (1 << 30), +}; + +/* + * IRQ-notification data record type: + */ +enum perf_record_type { + PERF_RECORD_SIMPLE, + PERF_RECORD_IRQ, + PERF_RECORD_GROUP, +}; + +/** + * struct hw_perf_counter - performance counter hardware details + */ +struct hw_perf_counter { + u64 config; + unsigned long config_base; + unsigned long counter_base; + int nmi; + unsigned int idx; + u64 prev_count; + s32 next_count; + u64 irq_period; +}; + +/* + * Hardcoded buffer length limit for now, for IRQ-fed events: + */ +#define PERF_DATA_BUFLEN 2048 + +/** + * struct perf_data - performance counter IRQ data sampling ... + */ +struct perf_data { + int len; + int rd_idx; + int overrun; + u8 data[PERF_DATA_BUFLEN]; +}; + +/** + * struct perf_counter - performance counter kernel representation: + */ +struct perf_counter { + struct list_head list; + int active; +#if BITS_PER_LONG == 64 + atomic64_t count; +#else + atomic_t count32[2]; +#endif + u64 __irq_period; + + struct hw_perf_counter hw; + + struct perf_counter_context *ctx; + struct task_struct *task; + + /* + * Protect attach/detach: + */ + struct mutex mutex; + + int oncpu; + int cpu; + + s32 hw_event_type; + enum perf_record_type record_type; + + /* read() / irq related data */ + wait_queue_head_t waitq; + /* optional: for NMIs */ + int wakeup_pending; + struct perf_data *irqdata; + struct perf_data *usrdata; + struct perf_data data[2]; +}; + +/** + * struct perf_counter_context - counter context structure + * + * Used as a container for task counters and CPU counters as well: + */ +struct perf_counter_context { +#ifdef CONFIG_PERF_COUNTERS + /* + * Protect the list of counters: + */ + spinlock_t lock; + struct list_head counters; + int nr_counters; + int nr_active; + struct task_struct *task; +#endif +}; + +/** + * struct perf_counter_cpu_context - per cpu counter context structure + */ +struct perf_cpu_context { + struct perf_counter_context ctx; + struct perf_counter_context *task_ctx; + int active_oncpu; + int max_pertask; +}; + +/* + * Set by architecture code: + */ +extern int perf_max_counters; + +#ifdef CONFIG_PERF_COUNTERS +extern void perf_counter_task_sched_in(struct task_struct *task, int cpu); +extern void perf_counter_task_sched_out(struct task_struct *task, int cpu); +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); +#else +static inline void +perf_counter_task_sched_in(struct task_struct *task, int cpu) { } +static inline void +perf_counter_task_sched_out(struct task_struct *task, int cpu) { } +static inline void +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) { } +#endif + +#endif /* _LINUX_PERF_COUNTER_H */ |