[PATCH 52/53] perf record: Toggle tailsize ring buffer for reading
From: Wang Nan <hidden>
Date: 2016-01-11 13:49:58
Also in:
lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
Toggel tailsize_evt_stopped director after receiving done or switch output. After this patch it is possible to trigger a dump use SIGUSR2 when something happen. Signed-off-by: Wang Nan <redacted> Signed-off-by: He Kuang <redacted> Cc: Arnaldo Carvalho de Melo <redacted> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <redacted> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <redacted> Cc: pi3orama@163.com --- tools/perf/builtin-record.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 6c8905b..6ec0529 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c@@ -591,6 +591,26 @@ static void record__init_features(struct record *rec) } static void +record__toggle_tailsize_evsels(struct record *rec, bool stop) +{ + struct perf_evsel *pos; + struct perf_evlist *evlist = rec->evlist; + + evlist__for_each(evlist, pos) { + if (!pos->tailsize) + continue; + if (!pos->overwrite) + continue; + if (stop) + perf_evsel__disable(pos); + else + perf_evsel__enable(pos); + } + + rec->tailsize_evt_stopped = stop; +} + +static void record__finish_output(struct record *rec) { struct perf_data_file *file = &rec->file;
@@ -925,6 +945,9 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) for (;;) { unsigned long long hits = rec->samples; + if (switch_output_started || done) + record__toggle_tailsize_evsels(rec, true); + if (record__mmap_read_all(rec) < 0) { auxtrace_snapshot_disable(); err = -1;
@@ -943,7 +966,20 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) } if (switch_output_started) { + /* + * SIGUSR2 raise after or during record__mmap_read_all(). + * continue to read again. + */ + if (!rec->tailsize_evt_stopped) + continue; + switch_output_started = 0; + /* + * Reenable events in tailsize ring buffer after + * record__mmap_read_all(): we have collected + * data from it. + */ + record__toggle_tailsize_evsels(rec, false); if (!quiet) fprintf(stderr, "[ perf record: dump data: Woken up %ld times ]\n",
--
1.8.3.4