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performance counters: core code

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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>
This commit is contained in:
Thomas Gleixner 2008-12-04 20:12:29 +01:00 • committed by Ingo Molnar
parent b5aa97e83b
commit 0793a61d4d
10 changed files with 1189 additions and 0 deletions
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9
include/linux/sched.h
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@ -71,6 +71,7 @@ struct sched_param {
#include <linux/fs_struct.h>
#include <linux/compiler.h>
#include <linux/completion.h>
#include <linux/perf_counter.h>
#include <linux/pid.h>
#include <linux/percpu.h>
#include <linux/topology.h>
@ -1326,6 +1327,7 @@ struct task_struct {
struct list_head pi_state_list;
struct futex_pi_state *pi_state_cache;
#endif
struct perf_counter_context perf_counter_ctx;
#ifdef CONFIG_NUMA
struct mempolicy *mempolicy;
short il_next;
@ -2285,6 +2287,13 @@ static inline void inc_syscw(struct task_struct *tsk)
#define TASK_SIZE_OF(tsk) TASK_SIZE
#endif
/*
* Call the function if the target task is executing on a CPU right now:
*/
extern void task_oncpu_function_call(struct task_struct *p,
void (*func) (void *info), void *info);
#ifdef CONFIG_MM_OWNER
extern void mm_update_next_owner(struct mm_struct *mm);
extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);