[PATCH 08/13] perf record: Split output into multiple files via '--switch-output'
From: Arnaldo Carvalho de Melo
Date: Fri Apr 29 2016 - 11:01:32 EST
From: Wang Nan <wangnan0@xxxxxxxxxx>
Allow 'perf record' to split 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.<timestamp> (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@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1461178794-40467-4-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
[ Added man page entry, used the re-synthesize patch in this series as a fixup ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-record.txt | 8 +++++++
tools/perf/builtin-record.c | 40 ++++++++++++++++++++++++++++++--
2 files changed, 46 insertions(+), 2 deletions(-)
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 19aa17532a16..a77a431ca4ef 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -347,6 +347,14 @@ Configure all used events to run in kernel space.
--all-user::
Configure all used events to run in user space.
+--switch-output::
+Generate multiple perf.data files, timestamp prefixed, switching to a new one
+when receiving a SIGUSR2.
+
+A possible use case is to, given an external event, slice the perf.data file
+that gets then processed, possibly via a perf script, to decide if that
+particular perf.data snapshot should be kept or not.
+
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-list[1]
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index f4710c82980f..8ebe953c7af0 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -58,6 +58,7 @@ struct record {
bool no_buildid_cache_set;
bool buildid_all;
bool timestamp_filename;
+ bool switch_output;
unsigned long long samples;
};
@@ -130,6 +131,7 @@ static volatile int child_finished;
static volatile int auxtrace_record__snapshot_started;
static DEFINE_TRIGGER(auxtrace_snapshot_trigger);
+static DEFINE_TRIGGER(switch_output_trigger);
static void sig_handler(int sig)
{
@@ -498,6 +500,8 @@ record__finish_output(struct record *rec)
return;
}
+static int record__synthesize(struct record *rec);
+
static int
record__switch_output(struct record *rec, bool at_exit)
{
@@ -526,6 +530,11 @@ record__switch_output(struct record *rec, bool at_exit)
if (!quiet)
fprintf(stderr, "[ perf record: Dump %s.%s ]\n",
file->path, timestamp);
+
+ /* Output tracking events */
+ if (!at_exit)
+ record__synthesize(rec);
+
return fd;
}
@@ -650,9 +659,12 @@ 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);
- trigger_on(&auxtrace_snapshot_trigger);
+ if (rec->opts.auxtrace_snapshot_mode)
+ trigger_on(&auxtrace_snapshot_trigger);
+ if (rec->switch_output)
+ trigger_on(&switch_output_trigger);
} else {
signal(SIGUSR2, SIG_IGN);
}
@@ -782,11 +794,13 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
}
trigger_ready(&auxtrace_snapshot_trigger);
+ trigger_ready(&switch_output_trigger);
for (;;) {
unsigned long long hits = rec->samples;
if (record__mmap_read_all(rec) < 0) {
trigger_error(&auxtrace_snapshot_trigger);
+ trigger_error(&switch_output_trigger);
err = -1;
goto out_child;
}
@@ -802,6 +816,22 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
}
}
+ if (trigger_is_hit(&switch_output_trigger)) {
+ trigger_ready(&switch_output_trigger);
+
+ 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");
+ trigger_error(&switch_output_trigger);
+ err = fd;
+ goto out_child;
+ }
+ }
+
if (hits == rec->samples) {
if (done || draining)
break;
@@ -830,6 +860,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
}
}
trigger_off(&auxtrace_snapshot_trigger);
+ trigger_off(&switch_output_trigger);
if (forks && workload_exec_errno) {
char msg[STRERR_BUFSIZE];
@@ -1263,6 +1294,8 @@ 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()
};
@@ -1417,4 +1450,7 @@ static void snapshot_sig_handler(int sig __maybe_unused)
if (auxtrace_record__snapshot_start(record.itr))
trigger_error(&auxtrace_snapshot_trigger);
}
+
+ if (trigger_is_ready(&switch_output_trigger))
+ trigger_hit(&switch_output_trigger);
}
--
2.5.5