[PATCH 2/2 ver 2] Block: use round_jiffies_up()

From: Alan Stern
Date: Wed Nov 05 2008 - 16:19:45 EST


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@xxxxxxxxxxxxxxxxxxx>

---

Index: usb-2.6/block/blk-timeout.c
===================================================================
--- usb-2.6.orig/block/blk-timeout.c
+++ usb-2.6/block/blk-timeout.c
@@ -75,14 +75,7 @@ void blk_delete_timer(struct request *re
{
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 lon
}

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))

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