Block: use round_jiffies_up()

This patch (as1159b) changes the timeout routines in the block core to
use round_jiffies_up().  There's no point in rounding the timer
deadline down, since if it expires too early we will have to restart
it.

The patch also removes some unnecessary tests when a request is
removed from the queue's timer list.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 972a63f..69185ea 100644 (file)
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -75,14 +75,7 @@ void blk_delete_timer(struct request *req)
 {
        struct request_queue *q = req->q;
 
-       /*
-        * Nothing to detach
-        */
-       if (!q->rq_timed_out_fn || !req->deadline)
-               return;
-
        list_del_init(&req->timeout_list);
-
        if (list_empty(&q->timeout_list))
                del_timer(&q->timeout);
 }
@@ -142,7 +135,7 @@ void blk_rq_timed_out_timer(unsigned long data)
        }
 
        if (next_set && !list_empty(&q->timeout_list))
-               mod_timer(&q->timeout, round_jiffies(next));
+               mod_timer(&q->timeout, round_jiffies_up(next));
 
        spin_unlock_irqrestore(q->queue_lock, flags);
 }
@@ -198,17 +191,10 @@ void blk_add_timer(struct request *req)
 
        /*
         * If the timer isn't already pending or this timeout is earlier
-        * than an existing one, modify the timer. Round to next nearest
+        * than an existing one, modify the timer. Round up to next nearest
         * second.
         */
-       expiry = round_jiffies(req->deadline);
-
-       /*
-        * We use ->deadline == 0 to detect whether a timer was added or
-        * not, so just increase to next jiffy for that specific case
-        */
-       if (unlikely(!req->deadline))
-               req->deadline = 1;
+       expiry = round_jiffies_up(req->deadline);
 
        if (!timer_pending(&q->timeout) ||
            time_before(expiry, q->timeout.expires))