md: use new plugging interface for RAID IO.

md/raid submits a lot of IO from the various raid threads.
So adding start/finish plug calls to those so that some
plugging happens.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index e867ee42b152..ce6960b1c682 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4478,11 +4478,13 @@ static void raid5d(mddev_t *mddev)
         struct stripe_head *sh;
         raid5_conf_t *conf = mddev->private;
         int handled;
+        struct blk_plug plug;
 
         pr_debug("+++ raid5d active\n");
 
         md_check_recovery(mddev);
 
+        blk_start_plug(&plug);
         handled = 0;
         spin_lock_irq(&conf->device_lock);
         while (1) {
@@ -4525,6 +4527,7 @@ static void raid5d(mddev_t *mddev)
         spin_unlock_irq(&conf->device_lock);
 
         async_tx_issue_pending_all();
+        blk_finish_plug(&plug);
 
         pr_debug("--- raid5d inactive\n");
 }