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-rw-r--r--tools/perf/util/mmap.c33
1 files changed, 15 insertions, 18 deletions
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 3f262e707a41..5f8cb1583e53 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -267,18 +267,6 @@ static int backward_rb_find_range(void *buf, int mask, u64 head, u64 *start, u64
return -1;
}
-static int rb_find_range(void *data, int mask, u64 head, u64 old,
- u64 *start, u64 *end, bool backward)
-{
- if (!backward) {
- *start = old;
- *end = head;
- return 0;
- }
-
- return backward_rb_find_range(data, mask, head, start, end);
-}
-
int perf_mmap__push(struct perf_mmap *md, bool backward,
void *to, int push(void *to, void *buf, size_t size))
{
@@ -290,19 +278,28 @@ int perf_mmap__push(struct perf_mmap *md, bool backward,
void *buf;
int rc = 0;
- if (rb_find_range(data, md->mask, head, old, &start, &end, backward))
- return -1;
+ start = backward ? head : old;
+ end = backward ? old : head;
if (start == end)
return 0;
size = end - start;
if (size > (unsigned long)(md->mask) + 1) {
- WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
+ if (!backward) {
+ WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
- md->prev = head;
- perf_mmap__consume(md, backward);
- return 0;
+ md->prev = head;
+ perf_mmap__consume(md, backward);
+ return 0;
+ }
+
+ /*
+ * Backward ring buffer is full. We still have a chance to read
+ * most of data from it.
+ */
+ if (backward_rb_find_range(data, md->mask, head, &start, &end))
+ return -1;
}
if ((start & md->mask) + size != (end & md->mask)) {