perf-record updates the header in the perf.data file at termination.
Without this update perf-report (and other processing builtins) cannot
properly read events from the file -- the algorithm in
__perf_session__process_events depends on the data_size which is read
from the file header and that function loops if data_size is 0.
Catch this condition when the file is opened and warn the user.
Signed-off-by: David Ahern <dsah...@gmail.com>
Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Stephane Eranian <eran...@google.com>
---
tools/perf/util/header.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 326068a..aa42c8c 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2802,6 +2802,18 @@ int perf_session__read_header(struct perf_session
*session, int fd)
if (perf_file_header__read(&f_header, header, fd) < 0)
return -EINVAL;
+ /*
+ * sanity check that perf.data was written cleanly: data size
+ * is initialized to 0 and updated only if the on_exit function
+ * is run. If data size is still 0 then the file cannot be
+ * processed.
+ */
+ if (f_header.data.size == 0) {
+ pr_err("data size is 0. "
+ "Was the record command properly terminated?\n");
+ return -1;
+ }
+
nr_attrs = f_header.attrs.size / f_header.attr_size;
lseek(fd, f_header.attrs.offset, SEEK_SET);
--
1.7.10.1
--
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