115 lines
2.1 KiB
C
115 lines
2.1 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* Copyright (C) 2013 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <getopt.h>
|
||
|
|
#include <sys/types.h>
|
||
|
|
#include <sys/stat.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
|
||
|
|
#include "tracefs.h"
|
||
|
|
#include "trace-local.h"
|
||
|
|
|
||
|
|
static void write_file(const char *name, char *val)
|
||
|
|
{
|
||
|
|
char *path;
|
||
|
|
int fd;
|
||
|
|
ssize_t n;
|
||
|
|
|
||
|
|
path = tracefs_get_tracing_file(name);
|
||
|
|
fd = open(path, O_WRONLY);
|
||
|
|
if (fd < 0)
|
||
|
|
die("writing %s", path);
|
||
|
|
|
||
|
|
n = write(fd, val, strlen(val));
|
||
|
|
if (n < 0)
|
||
|
|
die("failed to write to %s\n", path);
|
||
|
|
|
||
|
|
tracefs_put_tracing_file(path);
|
||
|
|
close(fd);
|
||
|
|
}
|
||
|
|
|
||
|
|
void trace_snapshot (int argc, char **argv)
|
||
|
|
{
|
||
|
|
const char *buffer = NULL;
|
||
|
|
const char *file = "snapshot";
|
||
|
|
struct stat st;
|
||
|
|
char *name;
|
||
|
|
char cpu_path[128];
|
||
|
|
int take_snap = 0;
|
||
|
|
int reset_snap = 0;
|
||
|
|
int free_snap = 0;
|
||
|
|
int cpu = -1;
|
||
|
|
int ret;
|
||
|
|
int c;
|
||
|
|
|
||
|
|
if (argc < 2)
|
||
|
|
usage(argv);
|
||
|
|
|
||
|
|
if (strcmp(argv[1], "snapshot") != 0)
|
||
|
|
usage(argv);
|
||
|
|
|
||
|
|
while ((c = getopt(argc-1, argv+1, "srfB:c:")) >= 0) {
|
||
|
|
switch (c) {
|
||
|
|
case 'h':
|
||
|
|
usage(argv);
|
||
|
|
break;
|
||
|
|
case 's':
|
||
|
|
take_snap = 1;
|
||
|
|
if (free_snap)
|
||
|
|
die("can't take snapshot and free it at the same time");
|
||
|
|
break;
|
||
|
|
case 'f':
|
||
|
|
free_snap = 1;
|
||
|
|
if (take_snap)
|
||
|
|
die("can't take snapshot and free it at the same time");
|
||
|
|
break;
|
||
|
|
case 'r':
|
||
|
|
reset_snap = 1;
|
||
|
|
break;
|
||
|
|
case 'B':
|
||
|
|
if (buffer)
|
||
|
|
die("Can only do one buffer at a time");
|
||
|
|
buffer = optarg;
|
||
|
|
break;
|
||
|
|
case 'c':
|
||
|
|
if (cpu >= 0)
|
||
|
|
die("Can only do one CPU (or all) at a time");
|
||
|
|
cpu = atoi(optarg);
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
usage(argv);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (cpu >= 0) {
|
||
|
|
snprintf(cpu_path, 128, "per_cpu/cpu%d/%s", cpu, file);
|
||
|
|
file = cpu_path;
|
||
|
|
}
|
||
|
|
|
||
|
|
name = tracefs_get_tracing_file(file);
|
||
|
|
ret = stat(name, &st);
|
||
|
|
if (ret < 0)
|
||
|
|
die("Snapshot feature is not supported by this kernel");
|
||
|
|
tracefs_put_tracing_file(name);
|
||
|
|
|
||
|
|
if (!reset_snap && !take_snap && !free_snap) {
|
||
|
|
show_file(file);
|
||
|
|
exit(0);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (reset_snap)
|
||
|
|
write_file(file, "2");
|
||
|
|
|
||
|
|
if (free_snap)
|
||
|
|
write_file(file, "0");
|
||
|
|
|
||
|
|
if (take_snap)
|
||
|
|
write_file(file, "1");
|
||
|
|
}
|