[PATCH v5 5/6] perf record: Re-synthesize tracking events after output switching

From: Wang Nan
Date: Mon Apr 18 2016 - 10:56:32 EST

Tracking events describe kernel and threads. They are generated by
reading /proc/kallsyms, /proc/*/maps and /proc/*/task/* during
initialization of 'perf record', serialized into event sequences and put
at the head of 'perf.data'. In case of output switching, each output
file should contain those events.

This patch calls record__synthesize() during output switching, so the
event sequences described above can be collected again.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
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/1460643725-167413-6-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
tools/perf/builtin-record.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index e4a1a3d..a199476 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -501,6 +501,8 @@ record__finish_output(struct record *rec)

+static int record__synthesize(struct record *rec);
static int
record__switch_output(struct record *rec, bool at_exit)
@@ -529,6 +531,11 @@ 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;