4 * Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org>
6 * Released under the GPL v2.
17 #include <subcmd/parse-options.h>
21 #include "thread_map.h"
22 #include "util/config.h"
25 #define DEFAULT_TRACER "function_graph"
28 struct perf_evlist *evlist;
35 static void sig_handler(int sig __maybe_unused)
41 * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
42 * we asked by setting its exec_error to the function below,
43 * ftrace__workload_exec_failed_signal.
45 * XXX We need to handle this more appropriately, emitting an error, etc.
47 static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
48 siginfo_t *info __maybe_unused,
49 void *ucontext __maybe_unused)
51 /* workload_exec_errno = info->si_value.sival_int; */
55 static int __write_tracing_file(const char *name, const char *val, bool append)
59 ssize_t size = strlen(val);
62 file = get_tracing_file(name);
64 pr_debug("cannot get tracing file: %s\n", name);
73 fd = open(file, flags);
75 pr_debug("cannot open tracing file: %s\n", name);
79 if (write(fd, val, size) == size)
82 pr_debug("write '%s' to tracing/%s failed\n", val, name);
86 put_tracing_file(file);
90 static int write_tracing_file(const char *name, const char *val)
92 return __write_tracing_file(name, val, false);
95 static int append_tracing_file(const char *name, const char *val)
97 return __write_tracing_file(name, val, true);
100 static int reset_tracing_cpu(void);
102 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
104 if (write_tracing_file("tracing_on", "0") < 0)
107 if (write_tracing_file("current_tracer", "nop") < 0)
110 if (write_tracing_file("set_ftrace_pid", " ") < 0)
113 if (reset_tracing_cpu() < 0)
119 static int set_tracing_pid(struct perf_ftrace *ftrace)
124 if (target__has_cpu(&ftrace->target))
127 for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) {
128 scnprintf(buf, sizeof(buf), "%d",
129 ftrace->evlist->threads->map[i]);
130 if (append_tracing_file("set_ftrace_pid", buf) < 0)
136 static int set_tracing_cpumask(struct cpu_map *cpumap)
143 last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
144 mask_size = (last_cpu + 3) / 4 + 1;
145 mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
147 cpumask = malloc(mask_size);
148 if (cpumask == NULL) {
149 pr_debug("failed to allocate cpu mask\n");
153 cpu_map__snprint_mask(cpumap, cpumask, mask_size);
155 ret = write_tracing_file("tracing_cpumask", cpumask);
161 static int set_tracing_cpu(struct perf_ftrace *ftrace)
163 struct cpu_map *cpumap = ftrace->evlist->cpus;
165 if (!target__has_cpu(&ftrace->target))
168 return set_tracing_cpumask(cpumap);
171 static int reset_tracing_cpu(void)
173 struct cpu_map *cpumap = cpu_map__new(NULL);
176 ret = set_tracing_cpumask(cpumap);
177 cpu_map__put(cpumap);
181 static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
186 struct pollfd pollfd = {
190 if (geteuid() != 0) {
191 pr_err("ftrace only works for root!\n");
195 signal(SIGINT, sig_handler);
196 signal(SIGUSR1, sig_handler);
197 signal(SIGCHLD, sig_handler);
198 signal(SIGPIPE, sig_handler);
200 if (reset_tracing_files(ftrace) < 0)
203 /* reset ftrace buffer */
204 if (write_tracing_file("trace", "0") < 0)
207 if (argc && perf_evlist__prepare_workload(ftrace->evlist,
208 &ftrace->target, argv, false,
209 ftrace__workload_exec_failed_signal) < 0) {
213 if (set_tracing_pid(ftrace) < 0) {
214 pr_err("failed to set ftrace pid\n");
218 if (set_tracing_cpu(ftrace) < 0) {
219 pr_err("failed to set tracing cpumask\n");
223 if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
224 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
228 trace_file = get_tracing_file("trace_pipe");
230 pr_err("failed to open trace_pipe\n");
234 trace_fd = open(trace_file, O_RDONLY);
236 put_tracing_file(trace_file);
239 pr_err("failed to open trace_pipe\n");
243 fcntl(trace_fd, F_SETFL, O_NONBLOCK);
244 pollfd.fd = trace_fd;
246 if (write_tracing_file("tracing_on", "1") < 0) {
247 pr_err("can't enable tracing\n");
253 perf_evlist__start_workload(ftrace->evlist);
256 if (poll(&pollfd, 1, -1) < 0)
259 if (pollfd.revents & POLLIN) {
260 int n = read(trace_fd, buf, sizeof(buf));
263 if (fwrite(buf, n, 1, stdout) != 1)
268 write_tracing_file("tracing_on", "0");
270 /* read remaining buffer contents */
272 int n = read(trace_fd, buf, sizeof(buf));
275 if (fwrite(buf, n, 1, stdout) != 1)
282 reset_tracing_files(ftrace);
284 return done ? 0 : -1;
287 static int perf_ftrace_config(const char *var, const char *value, void *cb)
289 struct perf_ftrace *ftrace = cb;
291 if (prefixcmp(var, "ftrace."))
294 if (strcmp(var, "ftrace.tracer"))
297 if (!strcmp(value, "function_graph") ||
298 !strcmp(value, "function")) {
299 ftrace->tracer = value;
303 pr_err("Please select \"function_graph\" (default) or \"function\"\n");
307 int cmd_ftrace(int argc, const char **argv)
310 struct perf_ftrace ftrace = {
311 .tracer = DEFAULT_TRACER,
312 .target = { .uid = UINT_MAX, },
314 const char * const ftrace_usage[] = {
315 "perf ftrace [<options>] [<command>]",
316 "perf ftrace [<options>] -- <command> [<options>]",
319 const struct option ftrace_options[] = {
320 OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
321 "tracer to use: function_graph(default) or function"),
322 OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
323 "trace on existing process id"),
324 OPT_INCR('v', "verbose", &verbose,
326 OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
327 "system-wide collection from all CPUs"),
328 OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
329 "list of cpus to monitor"),
333 ret = perf_config(perf_ftrace_config, &ftrace);
337 argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
338 PARSE_OPT_STOP_AT_NON_OPTION);
339 if (!argc && target__none(&ftrace.target))
340 usage_with_options(ftrace_usage, ftrace_options);
342 ret = target__validate(&ftrace.target);
346 target__strerror(&ftrace.target, ret, errbuf, 512);
347 pr_err("%s\n", errbuf);
351 ftrace.evlist = perf_evlist__new();
352 if (ftrace.evlist == NULL)
355 ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
357 goto out_delete_evlist;
359 ret = __cmd_ftrace(&ftrace, argc, argv);
362 perf_evlist__delete(ftrace.evlist);