diff options
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 3678d3d66c6..d09aac4a84e 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -505,7 +505,7 @@ void __req_mod(struct drbd_request *req, enum drbd_req_event what, * corresponding hlist_del is in _req_may_be_done() */ hlist_add_head(&req->colision, ar_hash_slot(mdev, req->sector)); - set_bit(UNPLUG_REMOTE, &mdev->flags); /* why? */ + set_bit(UNPLUG_REMOTE, &mdev->flags); D_ASSERT(req->rq_state & RQ_NET_PENDING); req->rq_state |= RQ_NET_QUEUED; @@ -536,6 +536,11 @@ void __req_mod(struct drbd_request *req, enum drbd_req_event what, * * Add req to the (now) current epoch (barrier). */ + /* otherwise we may lose an unplug, which may cause some remote + * io-scheduler timeout to expire, increasing maximum latency, + * hurting performance. */ + set_bit(UNPLUG_REMOTE, &mdev->flags); + /* see drbd_make_request_common, * just after it grabs the req_lock */ D_ASSERT(test_bit(CREATE_BARRIER, &mdev->flags) == 0); |