Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 895e3c5c authored by majianpeng's avatar majianpeng Committed by NeilBrown
Browse files

md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE. 



'sync' writes set both REQ_SYNC and REQ_NOIDLE.
O_DIRECT writes set REQ_SYNC but not REQ_NOIDLE.

We currently assume that a REQ_SYNC request will not be followed by
more requests and so set STRIPE_PREREAD_ACTIVE to expedite the
request.
This is appropriate for sync requests, but not for O_DIRECT requests.

So make the setting of STRIPE_PREREAD_ACTIVE conditional on REQ_NOIDLE
rather than REQ_SYNC.  This is consistent with the documented meaning
of REQ_NOIDLE:

        __REQ_NOIDLE,           /* don't anticipate more IO after this one */

Signed-off-by: default avatarJianpeng Ma <majianpeng@gmail.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent b7219ccb

drivers/md/raid5.c

+1 −1
Original line number Diff line number Diff line
@@ -4135,7 +4135,7 @@ static void make_request(struct mddev *mddev, struct bio * bi) 
			finish_wait(&conf->wait_for_overlap, &w);

			set_bit(STRIPE_HANDLE, &sh->state);

			clear_bit(STRIPE_DELAYED, &sh->state);

			if ((bi->bi_rw & REQ_SYNC) &&

			if ((bi->bi_rw & REQ_NOIDLE) &&

			    !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))

				atomic_inc(&conf->preread_active_stripes);

			mddev_check_plugged(mddev);