perf record: Add '--timestamp-filename' option to append timestamp to output file name

This option appends current timestamp to the output file name.

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.<timestamp> (90 samples) ]
  # ls
  perf.data.201512262226584

The timestamp will be useful for identifying each perf.data after the
'perf record' support for generating multiple output files gets
introduced.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1460535673-159866-5-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 49 insertions, 4 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 480033fb9b20..3239a6ec9d23 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -56,6 +56,7 @@ struct record {
         bool                    no_buildid_cache;
         bool                    no_buildid_cache_set;
         bool                    buildid_all;
+        bool                    timestamp_filename;
         unsigned long long      samples;
 };
 
@@ -531,6 +532,37 @@ 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;
 
 /*
@@ -865,11 +897,22 @@ 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];
+                const char *postfix = rec->timestamp_filename ?
+                                        ".<timestamp>" : "";
 
                 if (rec->samples && !rec->opts.full_auxtrace)
                         scnprintf(samples, sizeof(samples),
@@ -877,9 +920,9 @@ out_child:
                 else
                         samples[0] = '\0';
 
-                fprintf(stderr, "[ perf record: Captured and wrote %.3f MB %s%s ]\n",
+                fprintf(stderr, "[ perf record: Captured and wrote %.3f MB %s%s%s ]\n",
                         perf_data_file__size(file) / 1024.0 / 1024.0,
-                        file->path, samples);
+                        file->path, postfix, samples);
         }
 
 out_delete_session:
@@ -1249,6 +1292,8 @@ 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()
 };