perf header: Don't assume there's no attr info if no sample ids is provided

This primarily fixes perf-report, which didn't report the correct type
of event if perf-record was called to record one event different from
'cycles':

  $ perf record -e instructions true
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.007 MB perf.data (~295 samples) ]

  $ perf report | head -n1
    # Events: 7  cycles

LPU-Reference: <m3mxor6nex.fsf@gmail.com>
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
This commit is contained in:
Franck Bui-Huu 2010-11-30 12:50:14 +01:00 committed by Arnaldo Carvalho de Melo
parent d214afbd81
commit 60e677373b

View file

@ -946,11 +946,16 @@ perf_header__find_attr(u64 id, struct perf_header *header)
/*
* We set id to -1 if the data file doesn't contain sample
* ids. Check for this and avoid walking through the entire
* list of ids which may be large.
* ids. This can happen when the data file contains one type
* of event and in that case, the header can still store the
* event attribute information. Check for this and avoid
* walking through the entire list of ids which may be large.
*/
if (id == -1ULL)
if (id == -1ULL) {
if (header->attrs > 0)
return &header->attr[0]->attr;
return NULL;
}
for (i = 0; i < header->attrs; i++) {
struct perf_header_attr *attr = header->attr[i];