[PATCH 24/46] perf record: Split output into multiple files via '--switch-output'

Wang Nan
2016-02-26T09:49:08Z

Allow 'perf record' splits its output into multiple files.

For example:

# ~/perf record -a --timestamp-filename --switch-output &
[1] 10763
# kill -s SIGUSR2 10763
[ perf record: dump data: Woken up 1 times ]
# [ perf record: Dump perf.data.2015122622314468 ]

# kill -s SIGUSR2 10763
[ perf record: dump data: Woken up 1 times ]
# [ perf record: Dump perf.data.2015122622314762 ]

# kill -s SIGUSR2 10763
[ perf record: dump data: Woken up 1 times ]
#[ perf record: Dump perf.data.2015122622315171 ]

# fg
perf record -a --timestamp-filename --switch-output
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Dump perf.data.2015122622315513 ]
[ perf record: Captured and wrote 0.014 MB perf.data (296 samples) ]

# ls -l
total 920
-rw------- 1 root root 797692 Dec 26 22:31 perf.data.2015122622314468
-rw------- 1 root root 59960 Dec 26 22:31 perf.data.2015122622314762
-rw------- 1 root root 59912 Dec 26 22:31 perf.data.2015122622315171
-rw------- 1 root root 19220 Dec 26 22:31 perf.data.2015122622315513

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: He Kuang <hekuang@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
---
tools/perf/builtin-record.c | 34 ++++++++++++++++++++++++++++------
1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index b982eec..897d720 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -56,6 +56,7 @@ struct record {
bool no_buildid_cache_set;
bool buildid_all;
bool timestamp_filename;
+ bool switch_output;
unsigned long long samples;
};

@@ -164,6 +165,7 @@ auxtrace_snapshot_is_enabled(void)

static volatile int auxtrace_snapshot_err;
static volatile int auxtrace_record__snapshot_started;
+static volatile int switch_output_started;

static void sig_handler(int sig)
{
@@ -666,7 +668,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
signal(SIGINT, sig_handler);
signal(SIGTERM, sig_handler);

- if (rec->opts.auxtrace_snapshot_mode) {
+ if (rec->opts.auxtrace_snapshot_mode || rec->switch_output) {
signal(SIGUSR2, snapshot_sig_handler);
auxtrace_snapshot_on();
} else {
@@ -818,9 +820,25 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
}
}

+ if (switch_output_started) {
+ switch_output_started = 0;
+
+ if (!quiet)
+ fprintf(stderr, "[ perf record: dump data: Woken up %ld times ]\n",
+ waking);
+ waking = 0;
+ fd = record__switch_output(rec, false);
+ if (fd < 0) {
+ pr_err("Failed to switch to new file\n");
+ err = fd;
+ goto out_child;
+ }
+ }
+
if (hits == rec->samples) {
if (done || draining)
break;
+
err = perf_evlist__poll(rec->evlist, -1);
/*
* Propagate error, only if there's any. Ignore positive
@@ -1274,6 +1292,8 @@ struct option __record_options[] = {
"Record build-id of all DSOs regardless of hits"),
OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename,
"append timestamp to output filename"),
+ OPT_BOOLEAN(0, "switch-output", &record.switch_output,
+ "Switch output when receive SIGUSR2"),
OPT_END()
};

@@ -1414,9 +1434,11 @@ out_symbol_exit:

static void snapshot_sig_handler(int sig __maybe_unused)
{
- if (!auxtrace_snapshot_is_enabled())
- return;
- auxtrace_snapshot_disable();
- auxtrace_snapshot_err = auxtrace_record__snapshot_start(record.itr);
- auxtrace_record__snapshot_started = 1;
+ if (auxtrace_snapshot_is_enabled()) {
+ auxtrace_snapshot_disable();
+ auxtrace_snapshot_err = auxtrace_record__snapshot_start(record.itr);
+ auxtrace_record__snapshot_started = 1;
+ }
+
+ switch_output_started = 1;
}
--
1.8.3.4