[PATCH 23/46] perf record: Add '--timestamp-filename' option to append timestamp to output filename

Wang Nan
2016-02-26T09:49:04Z

This options append current timestamp to output. For example:

# perf record -a --timestamp-filename
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Dump perf.data.2015122622265847 ]
[ perf record: Captured and wrote 0.742 MB perf.data (90 samples) ]
# ls
perf.data.201512262226584

After 'perf record' support generating multiple output files, timestamp
would be useful to identify each of them.

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 | 47 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 45 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 31aa1d4..b982eec 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -55,6 +55,7 @@ struct record {
bool no_buildid_cache;
bool no_buildid_cache_set;
bool buildid_all;
+ bool timestamp_filename;
unsigned long long samples;
};

@@ -527,6 +528,37 @@ record__finish_output(struct record *rec)
return;
}

+static int
+record__switch_output(struct record *rec, bool at_exit)
+{
+ struct perf_data_file *file = &rec->file;
+ int fd, err;
+
+ /* Same Size: "2015122520103046"*/
+ char timestamp[] = "InvalidTimestamp";
+
+ rec->samples = 0;
+ record__finish_output(rec);
+ err = fetch_current_timestamp(timestamp, sizeof(timestamp));
+ if (err) {
+ pr_err("Failed to get current timestamp\n");
+ return -EINVAL;
+ }
+
+ fd = perf_data_file__switch(file, timestamp,
+ rec->session->header.data_offset,
+ at_exit);
+ if (fd >= 0 && !at_exit) {
+ rec->bytes_written = 0;
+ rec->session->header.data_size = 0;
+ }
+
+ if (!quiet)
+ fprintf(stderr, "[ perf record: Dump %s.%s ]\n",
+ file->path, timestamp);
+ return fd;
+}
+
static volatile int workload_exec_errno;

/*
@@ -847,8 +879,17 @@ out_child:
/* this will be recalculated during process_buildids() */
rec->samples = 0;

- if (!err)
- record__finish_output(rec);
+ if (!err) {
+ if (!rec->timestamp_filename) {
+ record__finish_output(rec);
+ } else {
+ fd = record__switch_output(rec, true);
+ if (fd < 0) {
+ status = fd;
+ goto out_delete_session;
+ }
+ }
+ }

if (!err && !quiet) {
char samples[128];
@@ -1231,6 +1272,8 @@ struct option __record_options[] = {
"file", "vmlinux pathname"),
OPT_BOOLEAN(0, "buildid-all", &record.buildid_all,
"Record build-id of all DSOs regardless of hits"),
+ OPT_BOOLEAN(0, "timestamp-filename", &record.timestamp_filename,
+ "append timestamp to output filename"),
OPT_END()
};

--
1.8.3.4