From 24ecfbe27f65563909b14492afda2f1c21f7c044 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@infradead.org>
Date: Mon, 18 Apr 2011 11:41:33 +0200
Subject: [PATCH] block: add blk_run_queue_async
Instead of overloading __blk_run_queue to force an offload to kblockd
add a new blk_run_queue_async helper to do it explicitly. I've kept
the blk_queue_stopped check for now, but I suspect it's not needed
as the check we do when the workqueue items runs should be enough.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
---
block/blk-core.c | 36 +++++++++++++++++++++-----------
block/blk-exec.c | 2 +-
block/blk-flush.c | 4 ++--
block/blk.h | 1 +
block/cfq-iosched.c | 6 +++---
block/elevator.c | 4 ++--
drivers/scsi/scsi_lib.c | 2 +-
drivers/scsi/scsi_transport_fc.c | 2 +-
include/linux/blkdev.h | 2 +-
9 files changed, 36 insertions(+), 23 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index e2bacfa46cc3e..5fa3dd2705c61 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -204,7 +204,7 @@ static void blk_delay_work(struct work_struct *work)
q = container_of(work, struct request_queue, delay_work.work);
spin_lock_irq(q->queue_lock);
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
spin_unlock_irq(q->queue_lock);
}
@@ -239,7 +239,7 @@ void blk_start_queue(struct request_queue *q)
WARN_ON(!irqs_disabled());
queue_flag_clear(QUEUE_FLAG_STOPPED, q);
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
}
EXPORT_SYMBOL(blk_start_queue);
@@ -296,11 +296,9 @@ EXPORT_SYMBOL(blk_sync_queue);
*
* Description:
* See @blk_run_queue. This variant must be called with the queue lock
- * held and interrupts disabled. If force_kblockd is true, then it is
- * safe to call this without holding the queue lock.
- *
+ * held and interrupts disabled.
*/
-void __blk_run_queue(struct request_queue *q, bool force_kblockd)
+void __blk_run_queue(struct request_queue *q)
{
if (unlikely(blk_queue_stopped(q)))
return;
@@ -309,7 +307,7 @@ void __blk_run_queue(struct request_queue *q, bool force_kblockd)
* Only recurse once to avoid overrunning the stack, let the unplug
* handling reinvoke the handler shortly if we already got there.
*/
- if (!force_kblockd && !queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
+ if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
q->request_fn(q);
queue_flag_clear(QUEUE_FLAG_REENTER, q);
} else
@@ -317,6 +315,20 @@ void __blk_run_queue(struct request_queue *q, bool force_kblockd)
}
EXPORT_SYMBOL(__blk_run_queue);
+/**
+ * blk_run_queue_async - run a single device queue in workqueue context
+ * @q: The queue to run
+ *
+ * Description:
+ * Tells kblockd to perform the equivalent of @blk_run_queue on behalf
+ * of us.
+ */
+void blk_run_queue_async(struct request_queue *q)
+{
+ if (likely(!blk_queue_stopped(q)))
+ queue_delayed_work(kblockd_workqueue, &q->delay_work, 0);
+}
+
/**
* blk_run_queue - run a single device queue
* @q: The queue to run
@@ -330,7 +342,7 @@ void blk_run_queue(struct request_queue *q)
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(blk_run_queue);
@@ -979,7 +991,7 @@ void blk_insert_request(struct request_queue *q, struct request *rq,
blk_queue_end_tag(q, rq);
add_acct_request(q, rq, where);
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(blk_insert_request);
@@ -1323,7 +1335,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
} else {
spin_lock_irq(q->queue_lock);
add_acct_request(q, req, where);
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
out_unlock:
spin_unlock_irq(q->queue_lock);
}
@@ -2684,9 +2696,9 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth,
*/
if (from_schedule) {
spin_unlock(q->queue_lock);
- __blk_run_queue(q, true);
+ blk_run_queue_async(q);
} else {
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
spin_unlock(q->queue_lock);
}
diff --git a/block/blk-exec.c b/block/blk-exec.c
index 7482b7fa863ba..81e31819a597b 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -55,7 +55,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
WARN_ON(irqs_disabled());
spin_lock_irq(q->queue_lock);
__elv_add_request(q, rq, where);
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
/* the queue is stopped so it won't be plugged+unplugged */
if (rq->cmd_type == REQ_TYPE_PM_RESUME)
q->request_fn(q);
diff --git a/block/blk-flush.c b/block/blk-flush.c
index eba4a2790c6c4..6c9b5e189e624 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -218,7 +218,7 @@ static void flush_end_io(struct request *flush_rq, int error)
* request_fn may confuse the driver. Always use kblockd.
*/
if (queued)
- __blk_run_queue(q, true);
+ blk_run_queue_async(q);
}
/**
@@ -274,7 +274,7 @@ static void flush_data_end_io(struct request *rq, int error)
* the comment in flush_end_io().
*/
if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error))
- __blk_run_queue(q, true);
+ blk_run_queue_async(q);
}
/**
diff --git a/block/blk.h b/block/blk.h
index 61263463e38e1..c9df8fc3c9997 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -22,6 +22,7 @@ void blk_rq_timed_out_timer(unsigned long data);
void blk_delete_timer(struct request *);
void blk_add_timer(struct request *);
void __generic_unplug_device(struct request_queue *);
+void blk_run_queue_async(struct request_queue *q);
/*
* Internal atomic flags for request handling
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 3be881ec95ad0..46b0a1d1d9257 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3368,7 +3368,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfqd->busy_queues > 1) {
cfq_del_timer(cfqd, cfqq);
cfq_clear_cfqq_wait_request(cfqq);
- __blk_run_queue(cfqd->queue, false);
+ __blk_run_queue(cfqd->queue);
} else {
cfq_blkiocg_update_idle_time_stats(
&cfqq->cfqg->blkg);
@@ -3383,7 +3383,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
* this new queue is RT and the current one is BE
*/
cfq_preempt_queue(cfqd, cfqq);
- __blk_run_queue(cfqd->queue, false);
+ __blk_run_queue(cfqd->queue);
}
}
@@ -3743,7 +3743,7 @@ static void cfq_kick_queue(struct work_struct *work)
struct request_queue *q = cfqd->queue;
spin_lock_irq(q->queue_lock);
- __blk_run_queue(cfqd->queue, false);
+ __blk_run_queue(cfqd->queue);
spin_unlock_irq(q->queue_lock);
}
diff --git a/block/elevator.c b/block/elevator.c
index 0cdb4e7ebab4e..6f6abc08bb565 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -642,7 +642,7 @@ void elv_quiesce_start(struct request_queue *q)
*/
elv_drain_elevator(q);
while (q->rq.elvpriv) {
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
spin_unlock_irq(q->queue_lock);
msleep(10);
spin_lock_irq(q->queue_lock);
@@ -695,7 +695,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
* with anything. There's no point in delaying queue
* processing.
*/
- __blk_run_queue(q, false);
+ __blk_run_queue(q);
break;
case ELEVATOR_INSERT_SORT_MERGE:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6d5c7ff43f5bd..ab55c2fa7ce20 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -443,7 +443,7 @@ static void scsi_run_queue(struct request_queue *q)
&sdev->request_queue->queue_flags);
if (flagset)
queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue);
- __blk_run_queue(sdev->request_queue, false);
+ __blk_run_queue(sdev->request_queue);
if (flagset)
queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue);
spin_unlock(sdev->request_queue->queue_lock);
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index fdf3fa639056c..28c33506e4ada 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -3829,7 +3829,7 @@ fc_bsg_goose_queue(struct fc_rport *rport)
!test_bit(QUEUE_FLAG_REENTER, &rport->rqst_q->queue_flags);
if (flagset)
queue_flag_set(QUEUE_FLAG_REENTER, rport->rqst_q);
- __blk_run_queue(rport->rqst_q, false);
+ __blk_run_queue(rport->rqst_q);
if (flagset)
queue_flag_clear(QUEUE_FLAG_REENTER, rport->rqst_q);
spin_unlock_irqrestore(rport->rqst_q->queue_lock, flags);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3448d89297e8c..cbbfd98ad4a3f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -697,7 +697,7 @@ extern void blk_start_queue(struct request_queue *q);
extern void blk_stop_queue(struct request_queue *q);
extern void blk_sync_queue(struct request_queue *q);
extern void __blk_stop_queue(struct request_queue *q);
-extern void __blk_run_queue(struct request_queue *q, bool force_kblockd);
+extern void __blk_run_queue(struct request_queue *q);
extern void blk_run_queue(struct request_queue *);
extern int blk_rq_map_user(struct request_queue *, struct request *,
struct rq_map_data *, void __user *, unsigned long,
--
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