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/*
* notify_group.c - self-sampling multuiple events in one group
*
* Copyright (c) 2009 Google, Inc
* Contributed by Stephane Eranian <eranian@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <sys/types.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <fcntl.h>
#include <err.h>
#include <sys/prctl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include "perf_util.h"
#define SMPL_PERIOD 2400000000ULL
typedef struct {
uint64_t ip;
} sample_t;
static volatile unsigned long notification_received;
static perf_event_desc_t *fds;
static int num_fds;
static int buffer_pages = 1; /* size of buffer payload (must be power of 2) */
static void
sigio_handler(int n, siginfo_t *info, struct sigcontext *sc)
{
struct perf_event_header ehdr;
uint64_t ip;
int id, ret;
id = perf_fd2event(fds, num_fds, info->si_fd);
if (id == -1)
errx(1, "cannot find event for descriptor %d", info->si_fd);
ret = perf_read_buffer(fds+id, &ehdr, sizeof(ehdr));
if (ret)
errx(1, "cannot read event header");
if (ehdr.type != PERF_RECORD_SAMPLE) {
warnx("unknown event type %d, skipping", ehdr.type);
perf_skip_buffer(fds+id, ehdr.size - sizeof(ehdr));
goto skip;
}
ret = perf_read_buffer(fds+id, &ip, sizeof(ip));
if (ret)
errx(1, "cannot read IP");
notification_received++;
printf("Notification %lu: 0x%"PRIx64" fd=%d %s\n",
notification_received,
ip,
info->si_fd, fds[id].name);
skip:
/*
* rearm the counter for one more shot
*/
ret = ioctl(info->si_fd, PERF_EVENT_IOC_REFRESH, 1);
if (ret == -1)
err(1, "cannot refresh");
}
/*
* infinite loop waiting for notification to get out
*/
void
busyloop(void)
{
/*
* busy loop to burn CPU cycles
*/
for(;notification_received < 1024;) ;
}
int
main(int argc, char **argv)
{
struct sigaction act;
size_t pgsz;
int ret, i;
ret = pfm_initialize();
if (ret != PFM_SUCCESS)
errx(1, "Cannot initialize library: %s", pfm_strerror(ret));
pgsz = sysconf(_SC_PAGESIZE);
/*
* Install the signal handler (SIGIO)
*/
memset(&act, 0, sizeof(act));
act.sa_sigaction = (void *)sigio_handler;
act.sa_flags = SA_SIGINFO;
sigaction (SIGIO, &act, 0);
/*
* allocates fd for us
*/
ret = perf_setup_list_events("cycles,"
"instructions,"
"cycles",
&fds, &num_fds);
if (ret || !num_fds)
exit(1);
fds[0].fd = -1;
for(i=0; i < num_fds; i++) {
/* want a notification for each sample added to the buffer */
fds[i].hw.disabled = !!i;
printf("i=%d disabled=%d\n", i, fds[i].hw.disabled);
fds[i].hw.wakeup_events = 1;
fds[i].hw.sample_type = PERF_SAMPLE_IP;
fds[i].hw.sample_period = SMPL_PERIOD;
fds[i].fd = perf_event_open(&fds[i].hw, 0, -1, fds[0].fd, 0);
if (fds[i].fd == -1) {
warn("cannot attach event %s", fds[i].name);
goto error;
}
fds[i].buf = mmap(NULL, (buffer_pages + 1)*pgsz, PROT_READ|PROT_WRITE, MAP_SHARED, fds[i].fd, 0);
if (fds[i].buf == MAP_FAILED)
err(1, "cannot mmap buffer");
/*
* setup asynchronous notification on the file descriptor
*/
ret = fcntl(fds[i].fd, F_SETFL, fcntl(fds[i].fd, F_GETFL, 0) | O_ASYNC);
if (ret == -1)
err(1, "cannot set ASYNC");
/*
* necessary if we want to get the file descriptor for
* which the SIGIO is sent for in siginfo->si_fd.
* SA_SIGINFO in itself is not enough
*/
ret = fcntl(fds[i].fd, F_SETSIG, SIGIO);
if (ret == -1)
err(1, "cannot setsig");
/*
* get ownership of the descriptor
*/
ret = fcntl(fds[i].fd, F_SETOWN, getpid());
if (ret == -1)
err(1, "cannot setown");
fds[i].pgmsk = (buffer_pages * pgsz) - 1;
}
for(i=0; i < num_fds; i++) {
ret = ioctl(fds[i].fd, PERF_EVENT_IOC_REFRESH , 1);
if (ret == -1)
err(1, "cannot refresh");
}
busyloop();
prctl(PR_TASK_PERF_EVENTS_DISABLE);
error:
/*
* destroy our session
*/
for(i=0; i < num_fds; i++)
if (fds[i].fd > -1)
close(fds[i].fd);
perf_free_fds(fds, num_fds);
/* free libpfm resources cleanly */
pfm_terminate();
return 0;
}