[PATCH V2 3/8] perf tools: reuse perf_mmap__read_catchup in perf_mmap__push

From: kan . liang
Date: Wed Dec 06 2017 - 18:34:57 EST


From: Kan Liang <kan.liang@xxxxxxxxx>

perf_mmap__push uses the same codes as perf_mmap__read_catchup to
calculate the ring buffer start, end and size.

No funcational change.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
---
tools/perf/util/mmap.c | 31 ++++++-------------------------
1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index bf67460..61237eb 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -285,36 +285,16 @@ int perf_mmap__push(struct perf_mmap *md, bool overwrite,
void *to, int push(void *to, void *buf, size_t size))
{
u64 head = perf_mmap__read_head(md);
- u64 old = md->prev;
- u64 end = head, start = old;
+ u64 end, start;
unsigned char *data = md->base + page_size;
unsigned long size;
void *buf;
- int rc = 0;
+ int rc;

- start = overwrite ? head : old;
- end = overwrite ? old : head;

- if (start == end)
- return 0;
-
- size = end - start;
- if (size > (unsigned long)(md->mask) + 1) {
- if (!overwrite) {
- WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
-
- md->prev = head;
- perf_mmap__consume(md, overwrite);
- return 0;
- }
-
- /*
- * Backward ring buffer is full. We still have a chance to read
- * most of data from it.
- */
- if (overwrite_rb_find_range(data, md->mask, head, &start, &end))
- return -1;
- }
+ rc = perf_mmap__read_catchup(md, overwrite, &start, &end, &size);
+ if (rc < 1)
+ return rc;

if ((start & md->mask) + size != (end & md->mask)) {
buf = &data[start & md->mask];
@@ -338,6 +318,7 @@ int perf_mmap__push(struct perf_mmap *md, bool overwrite,

md->prev = head;
perf_mmap__consume(md, overwrite);
+ rc = 0;
out:
return rc;
}
--
2.5.5