1 files changed, 76 insertions, 1 deletions

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 47cdc3ad6546..61aa381d05d0 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -158,7 +158,8 @@ static int perf_mmap__aio_mmap(struct perf_mmap *map, struct mmap_params *mp)
 {
 	int delta_max;
 
-	if (mp->nr_cblocks) {
+	map->aio.nr_cblocks = mp->nr_cblocks;
+	if (map->aio.nr_cblocks) {
 		map->aio.data = malloc(perf_mmap__mmap_len(map));
 		if (!map->aio.data) {
 			pr_debug2("failed to allocate data buffer, error %m\n");
@@ -187,6 +188,80 @@ static void perf_mmap__aio_munmap(struct perf_mmap *map)
 	if (map->aio.data)
 		zfree(&map->aio.data);
 }
+
+int perf_mmap__aio_push(struct perf_mmap *md, void *to,
+			int push(void *to, struct aiocb *cblock, void *buf, size_t size, off_t off),
+			off_t *off)
+{
+	u64 head = perf_mmap__read_head(md);
+	unsigned char *data = md->base + page_size;
+	unsigned long size, size0 = 0;
+	void *buf;
+	int rc = 0;
+
+	rc = perf_mmap__read_init(md);
+	if (rc < 0)
+		return (rc == -EAGAIN) ? 0 : -1;
+
+	/*
+	 * md->base data is copied into md->data buffer to
+	 * release space in the kernel buffer as fast as possible,
+	 * thru perf_mmap__consume() below.
+	 *
+	 * That lets the kernel to proceed with storing more
+	 * profiling data into the kernel buffer earlier than other
+	 * per-cpu kernel buffers are handled.
+	 *
+	 * Coping can be done in two steps in case the chunk of
+	 * profiling data crosses the upper bound of the kernel buffer.
+	 * In this case we first move part of data from md->start
+	 * till the upper bound and then the reminder from the
+	 * beginning of the kernel buffer till the end of
+	 * the data chunk.
+	 */
+
+	size = md->end - md->start;
+
+	if ((md->start & md->mask) + size != (md->end & md->mask)) {
+		buf = &data[md->start & md->mask];
+		size = md->mask + 1 - (md->start & md->mask);
+		md->start += size;
+		memcpy(md->aio.data, buf, size);
+		size0 = size;
+	}
+
+	buf = &data[md->start & md->mask];
+	size = md->end - md->start;
+	md->start += size;
+	memcpy(md->aio.data + size0, buf, size);
+
+	/*
+	 * Increment md->refcount to guard md->data buffer
+	 * from premature deallocation because md object can be
+	 * released earlier than aio write request started
+	 * on mmap->data is complete.
+	 *
+	 * perf_mmap__put() is done at record__aio_complete()
+	 * after started request completion.
+	 */
+	perf_mmap__get(md);
+
+	md->prev = head;
+	perf_mmap__consume(md);
+
+	rc = push(to, &md->aio.cblock, md->aio.data, size0 + size, *off);
+	if (!rc) {
+		*off += size0 + size;
+	} else {
+		/*
+		 * Decrement md->refcount back if aio write
+		 * operation failed to start.
+		 */
+		perf_mmap__put(md);
+	}
+
+	return rc;
+}
 #else
 static int perf_mmap__aio_mmap(struct perf_mmap *map __maybe_unused,
 			       struct mmap_params *mp __maybe_unused)