[PATCH V2 4/8] perf mmap: Using the stored data in perf_mmap__read_event

From: kan . liang
Date: Tue Mar 06 2018 - 10:39:21 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

Using the 'start', 'end' and 'overwrite' which are stored in
struct perf_mmap to replace the parameters of perf_mmap__read_event().
The parameters will be discarded later.

No functional change.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---

Changes since V1:
- Remove old startp/overwrite/end.

tools/perf/util/mmap.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 8c1d033..2933942 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -76,8 +76,9 @@ static union perf_event *perf_mmap__read(struct perf_mmap *map,
* perf_mmap__read_done()
*/
union perf_event *perf_mmap__read_event(struct perf_mmap *map,
- bool overwrite,
- u64 *startp, u64 end)
+ bool overwrite __maybe_unused,
+ u64 *startp __maybe_unused,
+ u64 end __maybe_unused)
{
union perf_event *event;

@@ -87,17 +88,14 @@ union perf_event *perf_mmap__read_event(struct perf_mmap *map,
if (!refcount_read(&map->refcnt))
return NULL;

- if (startp == NULL)
- return NULL;
-
/* non-overwirte doesn't pause the ringbuffer */
- if (!overwrite)
- end = perf_mmap__read_head(map);
+ if (!map->overwrite)
+ map->end = perf_mmap__read_head(map);

- event = perf_mmap__read(map, startp, end);
+ event = perf_mmap__read(map, &map->start, map->end);

- if (!overwrite)
- map->prev = *startp;
+ if (!map->overwrite)
+ map->prev = map->start;

return event;
}
--
2.4.11