Commit 794e43b5 authored May 05, 2010 by Tom Zanussi Committed by Frederic Weisbecker May 09, 2010

perf/live-mode: Handle payload-less events



Some events, such as the PERF_RECORD_FINISHED_ROUND event consist of
only an event header and no data.  In this case, a 0-length payload
will be read, and the 0 return value will be wrongly interpreted as an
'unexpected end of event stream'.

This patch allows for proper handling of data-less events by skipping
0-length reads.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <1273038527.6383.51.camel@tropicana>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

parent 2c193c73

tools/perf/util/session.c

+11 −8

Original line number	Diff line number	Diff line
		@@ -696,7 +696,9 @@ more:
		p = &event;
		p += sizeof(struct perf_event_header);

		err = do_read(self->fd, p, size - sizeof(struct perf_event_header));
		if (size - sizeof(struct perf_event_header)) {
		err = do_read(self->fd, p,
		size - sizeof(struct perf_event_header));
		if (err <= 0) {
		if (err == 0) {
		pr_err("unexpected end of event stream\n");
		@@ -706,6 +708,7 @@ more:
		pr_err("failed to read event data\n");
		goto out_err;
		}
		}

		if (size == 0 \|\|
		(skip = perf_session__process_event(self, &event, ops,

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