From: Namhyung Kim <namhyung....@lge.com> perf-record updates the header in the perf.data file at termination. Without this update perf-report (and other processing built-ins) it caused an infinite loop when perf report (or something like) called.
This is because the algorithm in __perf_session__process_events() depends on the data_size which is read from file header. Use file size directly instead in this case to do the best-effort processing. Signed-off-by: Namhyung Kim <namhy...@kernel.org> Tested-by: David Ahern <dsah...@gmail.com> Tested-by: Sonny Rao <sonny...@chromium.org> Acked-by: Ingo Molnar <mi...@kernel.org> Cc: David Ahern <dsah...@gmail.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Jiri Olsa <jo...@redhat.com> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <a.p.zijls...@chello.nl> Cc: Sonny Rao <sonny...@chromium.org> Link: http://lkml.kernel.org/r/1380529188-27193-1-git-send-email-namhy...@kernel.org Signed-off-by: David Ahern <dsah...@gmail.com> [ Reworded warning as per Ingo Molnar suggestion, replaces 'perf.data' with session->filename, to precisely identify the data file involved ] Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/header.c | 12 ++++++++++++ tools/perf/util/session.c | 2 +- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index ce69901176d8..c3e5a3b817ab 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2768,6 +2768,18 @@ int perf_session__read_header(struct perf_session *session) 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 contains only partial + * information. Just warn user and process it as much as it can. + */ + if (f_header.data.size == 0) { + pr_warning("WARNING: The %s file's data size field is 0 which is unexpected.\n" + "Was the 'perf record' command properly terminated?\n", + session->filename); + } + nr_attrs = f_header.attrs.size / f_header.attr_size; lseek(fd, f_header.attrs.offset, SEEK_SET); diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 37c4718f6be1..568b750c01f6 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1312,7 +1312,7 @@ int __perf_session__process_events(struct perf_session *session, file_offset = page_offset; head = data_offset - page_offset; - if (data_offset + data_size < file_size) + if (data_size && (data_offset + data_size < file_size)) file_size = data_offset + data_size; progress_next = file_size / 16; -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
