For SSDs, preserving a write stream reduces the number of active zones.
This is important for devices that restrict the number of active zones.
Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
block/mq-deadline.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index a73e16d3f8ac..3122c471f473 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -381,16 +381,14 @@ deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
* an unlocked target zone. For some HDDs, breaking a sequential
* write stream can lead to lower throughput, so make sure to preserve
* sequential write streams, even if that stream crosses into the next
- * zones and these zones are unlocked.
+ * zones and these zones are unlocked. For SSDs, do not break write
+ * streams to minimize the number of active zones.
*/
spin_lock_irqsave(&dd->zone_lock, flags);
while (rq) {
if (blk_req_can_dispatch_to_zone(rq))
break;
- if (blk_queue_nonrot(rq->q))
- rq = deadline_latter_request(rq);
- else
- rq = deadline_skip_seq_writes(dd, rq);
+ rq = deadline_skip_seq_writes(dd, rq);
}
spin_unlock_irqrestore(&dd->zone_lock, flags);
