linux/tools/perf/perf.h
Peter Zijlstra 974802eaa1 perf_counter: Add forward/backward attribute ABI compatibility
Provide for means of extending the perf_counter_attr in a 'natural' way.

We allow growing the structure by appending fields at the end by specifying
the full structure size inside it.

When a new kernel sees a smaller (old) structure, it will 0 pad the tail.
When an old kernel sees a larger (new) structure, it will verify the tail
consists of 0s, otherwise fail.

If we fail due to a size-mismatch, we return -E2BIG and write the kernel's
native attribe size back into the provided structure.

Furthermore, add some attribute verification, so that we'll fail counter
creation when unknown bits are present (PERF_SAMPLE, PERF_FORMAT, or in
the __reserved fields).

(This ABI detail is introduced while keeping the existing syscall ABI.)

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-12 14:28:52 +02:00

69 lines
1.6 KiB
C

#ifndef _PERF_PERF_H
#define _PERF_PERF_H
#if defined(__x86_64__) || defined(__i386__)
#include "../../arch/x86/include/asm/unistd.h"
#define rmb() asm volatile("lfence" ::: "memory")
#define cpu_relax() asm volatile("rep; nop" ::: "memory");
#endif
#ifdef __powerpc__
#include "../../arch/powerpc/include/asm/unistd.h"
#define rmb() asm volatile ("sync" ::: "memory")
#define cpu_relax() asm volatile ("" ::: "memory");
#endif
#include <time.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include "../../include/linux/perf_counter.h"
/*
* prctl(PR_TASK_PERF_COUNTERS_DISABLE) will (cheaply) disable all
* counters in the current task.
*/
#define PR_TASK_PERF_COUNTERS_DISABLE 31
#define PR_TASK_PERF_COUNTERS_ENABLE 32
#ifndef NSEC_PER_SEC
# define NSEC_PER_SEC 1000000000ULL
#endif
static inline unsigned long long rdclock(void)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ts.tv_sec * 1000000000ULL + ts.tv_nsec;
}
/*
* Pick up some kernel type conventions:
*/
#define __user
#define asmlinkage
#define unlikely(x) __builtin_expect(!!(x), 0)
#define min(x, y) ({ \
typeof(x) _min1 = (x); \
typeof(y) _min2 = (y); \
(void) (&_min1 == &_min2); \
_min1 < _min2 ? _min1 : _min2; })
static inline int
sys_perf_counter_open(struct perf_counter_attr *attr,
pid_t pid, int cpu, int group_fd,
unsigned long flags)
{
attr->size = sizeof(*attr);
return syscall(__NR_perf_counter_open, attr, pid, cpu,
group_fd, flags);
}
#define MAX_COUNTERS 256
#define MAX_NR_CPUS 256
#endif