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authorJens Axboe <axboe@suse.de>2006-07-20 14:54:05 +0200
committerJens Axboe <axboe@nelson.home.kernel.dk>2006-09-30 20:29:40 +0200
commitdc72ef4ae35c2016fb594bcc85ce871376682174 (patch)
treec0c78879addf0d65adcc8f8cce01165fa2502dac /block
parent981a79730d586335ef8f942c83bdf2b1de6d4e3d (diff)
downloadlinux-2.6.34-ux500-dc72ef4ae35c2016fb594bcc85ce871376682174.tar.gz
[PATCH] Add blk_start_queueing() helper
CFQ implements this on its own now, but it's really block layer knowledge. Tells a device queue to start dispatching requests to the driver, taking care to unplug if needed. Also fixes the issue where as/cfq will invoke a stopped queue, which we really don't want. Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'block')
-rw-r--r--block/as-iosched.c3
-rw-r--r--block/cfq-iosched.c22
-rw-r--r--block/ll_rw_blk.c25
3 files changed, 25 insertions, 25 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c
index f6dc9548931..bc13dc0b29b 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -1280,8 +1280,7 @@ static void as_work_handler(void *data)
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
- if (!as_queue_empty(q))
- q->request_fn(q);
+ blk_start_queueing(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 6fb1613d44d..9f684cc66bd 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1553,19 +1553,6 @@ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
}
/*
- * should really be a ll_rw_blk.c helper
- */
-static void cfq_start_queueing(struct cfq_data *cfqd, struct cfq_queue *cfqq)
-{
- request_queue_t *q = cfqd->queue;
-
- if (!blk_queue_plugged(q))
- q->request_fn(q);
- else
- __generic_unplug_device(q);
-}
-
-/*
* Called when a new fs request (rq) is added (to cfqq). Check if there's
* something we should do about it
*/
@@ -1593,7 +1580,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
if (cic == cfqd->active_cic &&
del_timer(&cfqd->idle_slice_timer)) {
cfq_slice_expired(cfqd, 0);
- cfq_start_queueing(cfqd, cfqq);
+ blk_start_queueing(cfqd->queue);
}
return;
}
@@ -1614,7 +1601,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
if (cfq_cfqq_wait_request(cfqq)) {
cfq_mark_cfqq_must_dispatch(cfqq);
del_timer(&cfqd->idle_slice_timer);
- cfq_start_queueing(cfqd, cfqq);
+ blk_start_queueing(cfqd->queue);
}
} else if (cfq_should_preempt(cfqd, cfqq, rq)) {
/*
@@ -1624,7 +1611,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
*/
cfq_preempt_queue(cfqd, cfqq);
cfq_mark_cfqq_must_dispatch(cfqq);
- cfq_start_queueing(cfqd, cfqq);
+ blk_start_queueing(cfqd->queue);
}
}
@@ -1832,8 +1819,7 @@ static void cfq_kick_queue(void *data)
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
- blk_remove_plug(q);
- q->request_fn(q);
+ blk_start_queueing(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index c6dfa889206..346be9ae31f 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -2267,6 +2267,25 @@ struct request *blk_get_request(request_queue_t *q, int rw, gfp_t gfp_mask)
EXPORT_SYMBOL(blk_get_request);
/**
+ * blk_start_queueing - initiate dispatch of requests to device
+ * @q: request queue to kick into gear
+ *
+ * This is basically a helper to remove the need to know whether a queue
+ * is plugged or not if someone just wants to initiate dispatch of requests
+ * for this queue.
+ *
+ * The queue lock must be held with interrupts disabled.
+ */
+void blk_start_queueing(request_queue_t *q)
+{
+ if (!blk_queue_plugged(q))
+ q->request_fn(q);
+ else
+ __generic_unplug_device(q);
+}
+EXPORT_SYMBOL(blk_start_queueing);
+
+/**
* blk_requeue_request - put a request back on queue
* @q: request queue where request should be inserted
* @rq: request to be inserted
@@ -2333,11 +2352,7 @@ void blk_insert_request(request_queue_t *q, struct request *rq,
drive_stat_acct(rq, rq->nr_sectors, 1);
__elv_add_request(q, rq, where, 0);
-
- if (blk_queue_plugged(q))
- __generic_unplug_device(q);
- else
- q->request_fn(q);
+ blk_start_queueing(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}