提交 529870e3 编写于 作者: T Tom Zanussi 提交者: Ingo Molnar

perf record: Introduce special handling for pipe output

Adds special treatment for stdout - if the user specifies '-o -'
to perf record, the intent is that the event stream be written
to stdout rather than to a disk file.

Also, redirect stdout of forked child to stderr - in pipe mode,
stdout of the forked child interferes with the stdout perf
stream, so redirect it to stderr where it can still be seen but
won't be mixed in with the perf output.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
上级 8dc58101
......@@ -35,6 +35,7 @@ static unsigned int page_size;
static unsigned int mmap_pages = 128;
static int freq = 1000;
static int output;
static int pipe_output = 0;
static const char *output_name = "perf.data";
static int group = 0;
static unsigned int realtime_prio = 0;
......@@ -449,7 +450,9 @@ static int __cmd_record(int argc, const char **argv)
exit(-1);
}
if (!stat(output_name, &st) && st.st_size) {
if (!strcmp(output_name, "-"))
pipe_output = 1;
else if (!stat(output_name, &st) && st.st_size) {
if (!force) {
if (!append_file) {
pr_err("Error, output file %s exists, use -A "
......@@ -474,7 +477,10 @@ static int __cmd_record(int argc, const char **argv)
else
flags |= O_TRUNC;
output = open(output_name, flags, S_IRUSR|S_IWUSR);
if (pipe_output)
output = STDOUT_FILENO;
else
output = open(output_name, flags, S_IRUSR | S_IWUSR);
if (output < 0) {
perror("failed to create output file");
exit(-1);
......@@ -513,6 +519,8 @@ static int __cmd_record(int argc, const char **argv)
}
if (!child_pid) {
if (pipe_output)
dup2(2, 1);
close(child_ready_pipe[0]);
close(go_pipe[1]);
fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
......@@ -564,7 +572,11 @@ static int __cmd_record(int argc, const char **argv)
open_counters(cpumap[i]);
}
if (file_new) {
if (pipe_output) {
err = perf_header__write_pipe(output);
if (err < 0)
return err;
} else if (file_new) {
err = perf_header__write(&session->header, output, false);
if (err < 0)
return err;
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册