[PATCH 03/25] perf trace: Add support for tracing workload given by command line

From: Arnaldo Carvalho de Melo
Date: Mon Oct 08 2012 - 18:33:26 EST


From: Namhyung Kim <namhyung.kim@xxxxxxx>

Now perf trace is able to trace specified workload by forking it like
perf record does. And also finish the tracing if the workload quits or
gets SIGINT.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1349413336-26936-5-git-send-email-namhyung@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-trace.c | 43 ++++++++++++++++++++++++++++++++++++-------
1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index da1183f..4e9320b 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -52,6 +52,13 @@ struct trace {
struct perf_record_opts opts;
};

+static bool done = false;
+
+static void sig_handler(int sig __maybe_unused)
+{
+ done = true;
+}
+
static int trace__read_syscall_info(struct trace *trace, int id)
{
char tp_name[128];
@@ -189,11 +196,12 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
return 0;
}

-static int trace__run(struct trace *trace)
+static int trace__run(struct trace *trace, int argc, const char **argv)
{
struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);
struct perf_evsel *evsel;
int err = -1, i, nr_events = 0, before;
+ const bool forks = argc > 0;

if (evlist == NULL) {
printf("Not enough memory to run!\n");
@@ -214,6 +222,17 @@ static int trace__run(struct trace *trace)

perf_evlist__config_attrs(evlist, &trace->opts);

+ signal(SIGCHLD, sig_handler);
+ signal(SIGINT, sig_handler);
+
+ if (forks) {
+ err = perf_evlist__prepare_workload(evlist, &trace->opts, argv);
+ if (err < 0) {
+ printf("Couldn't run the workload!\n");
+ goto out_delete_evlist;
+ }
+ }
+
err = perf_evlist__open(evlist);
if (err < 0) {
printf("Couldn't create the events: %s\n", strerror(errno));
@@ -227,6 +246,10 @@ static int trace__run(struct trace *trace)
}

perf_evlist__enable(evlist);
+
+ if (forks)
+ perf_evlist__start_workload(evlist);
+
again:
before = nr_events;

@@ -272,8 +295,15 @@ again:
}
}

- if (nr_events == before)
+ if (nr_events == before) {
+ if (done)
+ goto out_delete_evlist;
+
poll(evlist->pollfd, evlist->nr_fds, -1);
+ }
+
+ if (done)
+ perf_evlist__disable(evlist);

goto again;

@@ -286,7 +316,8 @@ out:
int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
{
const char * const trace_usage[] = {
- "perf trace [<options>]",
+ "perf trace [<options>] [<command>]",
+ "perf trace [<options>] -- <command> [<options>]",
NULL
};
struct trace trace = {
@@ -326,8 +357,6 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
char bf[BUFSIZ];

argc = parse_options(argc, argv, trace_options, trace_usage, 0);
- if (argc)
- usage_with_options(trace_usage, trace_options);

err = perf_target__validate(&trace.opts.target);
if (err) {
@@ -343,8 +372,8 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
return err;
}

- if (perf_target__none(&trace.opts.target))
+ if (!argc && perf_target__none(&trace.opts.target))
trace.opts.target.system_wide = true;

- return trace__run(&trace);
+ return trace__run(&trace, argc, argv);
}
--
1.7.9.2.358.g22243

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