[tip:perf/core] perf data: Enable stream flush within processing

[tip-bot for Jiri Olsa <tipbot@zytor.com>]

Commit-ID:  89e5fa884df8cd72e81c3727cf1f0d1c7a9c7641
Gitweb:     http://git.kernel.org/tip/89e5fa884df8cd72e81c3727cf1f0d1c7a9c7641
Author:     Jiri Olsa <jolsa@kernel.org>
AuthorDate: Sat, 18 Apr 2015 17:50:16 +0200
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 29 Apr 2015 10:37:48 -0300

perf data: Enable stream flush within processing

For big data files the size of data allocated for stream instance could
get really high. It's needed to flush the data out of the stream once in
a while.

Unfortunately there's no size indication in the stream object, so we
govern the flush based on the number of stored events. Current flush
limit is set ot 100000 events.

Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1429372220-6406-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/data-convert-bt.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c
index 0a2d7a5..4f942b3 100644
--- a/tools/perf/util/data-convert-bt.c
+++ b/tools/perf/util/data-convert-bt.c
@@ -43,6 +43,7 @@ struct evsel_priv {
 struct ctf_stream {
 	struct bt_ctf_stream *stream;
 	int cpu;
+	u32 count;
 };
 
 struct ctf_writer {
@@ -392,7 +393,10 @@ static int ctf_stream__flush(struct ctf_stream *cs)
 		if (err)
 			pr_err("CTF stream %d flush failed\n", cs->cpu);
 
-		pr("Flush stream for cpu %d\n", cs->cpu);
+		pr("Flush stream for cpu %d (%u samples)\n",
+		   cs->cpu, cs->count);
+
+		cs->count = 0;
 	}
 
 	return err;
@@ -490,6 +494,19 @@ static int get_sample_cpu(struct ctf_writer *cw, struct perf_sample *sample,
 	return cpu;
 }
 
+#define STREAM_FLUSH_COUNT 100000
+
+/*
+ * Currently we have no other way to determine the
+ * time for the stream flush other than keep track
+ * of the number of events and check it against
+ * threshold.
+ */
+static bool is_flush_needed(struct ctf_stream *cs)
+{
+	return cs->count >= STREAM_FLUSH_COUNT;
+}
+
 static int process_sample_event(struct perf_tool *tool,
 				union perf_event *_event __maybe_unused,
 				struct perf_sample *sample,
@@ -535,8 +552,13 @@ static int process_sample_event(struct perf_tool *tool,
 	}
 
 	cs = ctf_stream(cw, get_sample_cpu(cw, sample, evsel));
-	if (cs)
+	if (cs) {
+		if (is_flush_needed(cs))
+			ctf_stream__flush(cs);
+
+		cs->count++;
 		bt_ctf_stream_append_event(cs->stream, event);
+	}
 
 	bt_ctf_event_put(event);
 	return cs ? 0 : -1;