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Commit 83c38830 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
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drbd: performance - don't lose unplug events 



Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent e656ec8a

drivers/block/drbd/drbd_req.c

+6 −1
Original line number Diff line number Diff line
@@ -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);