diff options
| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-10-08 22:07:29 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-10-08 22:11:02 +0200 |
| commit | 26dd2cb074d9dc41c9e3cddd7bf175fd0a41febc (patch) | |
| tree | 05c0188d5ecf806e4079181989f971efa3c44d47 /tools | |
| parent | 97ea1a7fa62af0d8d49a0fc12796b0073537c9d8 (diff) | |
perf tools: Provide backward compatibility with previous perf.data version
We have merged the trace.info file into perf.data by adding one
section in the perf headers. This makes it incompatible with
previous version: the new perf tools can't read the older
perf.data.
To support the previous format, we check the headers size. If they
have the same size than in the previous format, then ignore the
trace info section that doesn't exist.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1255032449-12022-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/header.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 212fade7ee7..9aae360c0f2 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -287,10 +287,16 @@ struct perf_header *perf_header__read(int fd) do_read(fd, &f_header, sizeof(f_header)); if (f_header.magic != PERF_MAGIC || - f_header.size != sizeof(f_header) || f_header.attr_size != sizeof(f_attr)) die("incompatible file format"); + if (f_header.size != sizeof(f_header)) { + /* Support the previous format */ + if (f_header.size == offsetof(typeof(f_header), trace_info)) + f_header.trace_info.size = 0; + else + die("incompatible file format"); + } nr_attrs = f_header.attrs.size / sizeof(f_attr); lseek(fd, f_header.attrs.offset, SEEK_SET); |