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-rw-r--r--block/blk-core.c540
-rw-r--r--block/blk-exec.c4
-rw-r--r--block/blk-flush.c6
-rw-r--r--block/blk-settings.c8
-rw-r--r--block/blk-throttle.c4
-rw-r--r--block/blk.h2
-rw-r--r--block/cfq-iosched.c8
-rw-r--r--block/deadline-iosched.c9
-rw-r--r--block/elevator.c49
-rw-r--r--block/noop-iosched.c8
10 files changed, 323 insertions, 315 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 74d496ccf4d7..e1fcf7a24668 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -27,6 +27,7 @@
#include <linux/writeback.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/fault-inject.h>
+#include <linux/list_sort.h>
#define CREATE_TRACE_POINTS
#include <trace/events/block.h>
@@ -198,135 +199,43 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
EXPORT_SYMBOL(blk_dump_rq_flags);
/*
- * "plug" the device if there are no outstanding requests: this will
- * force the transfer to start only after we have put all the requests
- * on the list.
- *
- * This is called with interrupts off and no requests on the queue and
- * with the queue lock held.
- */
-void blk_plug_device(struct request_queue *q)
+ * Make sure that plugs that were pending when this function was entered,
+ * are now complete and requests pushed to the queue.
+*/
+static inline void queue_sync_plugs(struct request_queue *q)
{
- WARN_ON(!irqs_disabled());
-
/*
- * don't plug a stopped queue, it must be paired with blk_start_queue()
- * which will restart the queueing
+ * If the current process is plugged and has barriers submitted,
+ * we will livelock if we don't unplug first.
*/
- if (blk_queue_stopped(q))
- return;
-
- if (!queue_flag_test_and_set(QUEUE_FLAG_PLUGGED, q)) {
- mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
- trace_block_plug(q);
- }
-}
-EXPORT_SYMBOL(blk_plug_device);
-
-/**
- * blk_plug_device_unlocked - plug a device without queue lock held
- * @q: The &struct request_queue to plug
- *
- * Description:
- * Like @blk_plug_device(), but grabs the queue lock and disables
- * interrupts.
- **/
-void blk_plug_device_unlocked(struct request_queue *q)
-{
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- blk_plug_device(q);
- spin_unlock_irqrestore(q->queue_lock, flags);
-}
-EXPORT_SYMBOL(blk_plug_device_unlocked);
-
-/*
- * remove the queue from the plugged list, if present. called with
- * queue lock held and interrupts disabled.
- */
-int blk_remove_plug(struct request_queue *q)
-{
- WARN_ON(!irqs_disabled());
-
- if (!queue_flag_test_and_clear(QUEUE_FLAG_PLUGGED, q))
- return 0;
-
- del_timer(&q->unplug_timer);
- return 1;
+ blk_flush_plug(current);
}
-EXPORT_SYMBOL(blk_remove_plug);
-/*
- * remove the plug and let it rip..
- */
-void __generic_unplug_device(struct request_queue *q)
+static void blk_delay_work(struct work_struct *work)
{
- if (unlikely(blk_queue_stopped(q)))
- return;
- if (!blk_remove_plug(q) && !blk_queue_nonrot(q))
- return;
+ struct request_queue *q;
- q->request_fn(q);
+ q = container_of(work, struct request_queue, delay_work.work);
+ spin_lock_irq(q->queue_lock);
+ __blk_run_queue(q, false);
+ spin_unlock_irq(q->queue_lock);
}
/**
- * generic_unplug_device - fire a request queue
- * @q: The &struct request_queue in question
+ * blk_delay_queue - restart queueing after defined interval
+ * @q: The &struct request_queue in question
+ * @msecs: Delay in msecs
*
* Description:
- * Linux uses plugging to build bigger requests queues before letting
- * the device have at them. If a queue is plugged, the I/O scheduler
- * is still adding and merging requests on the queue. Once the queue
- * gets unplugged, the request_fn defined for the queue is invoked and
- * transfers started.
- **/
-void generic_unplug_device(struct request_queue *q)
-{
- if (blk_queue_plugged(q)) {
- spin_lock_irq(q->queue_lock);
- __generic_unplug_device(q);
- spin_unlock_irq(q->queue_lock);
- }
-}
-EXPORT_SYMBOL(generic_unplug_device);
-
-static void blk_backing_dev_unplug(struct backing_dev_info *bdi,
- struct page *page)
-{
- struct request_queue *q = bdi->unplug_io_data;
-
- blk_unplug(q);
-}
-
-void blk_unplug_work(struct work_struct *work)
-{
- struct request_queue *q =
- container_of(work, struct request_queue, unplug_work);
-
- trace_block_unplug_io(q);
- q->unplug_fn(q);
-}
-
-void blk_unplug_timeout(unsigned long data)
-{
- struct request_queue *q = (struct request_queue *)data;
-
- trace_block_unplug_timer(q);
- kblockd_schedule_work(q, &q->unplug_work);
-}
-
-void blk_unplug(struct request_queue *q)
+ * Sometimes queueing needs to be postponed for a little while, to allow
+ * resources to come back. This function will make sure that queueing is
+ * restarted around the specified time.
+ */
+void blk_delay_queue(struct request_queue *q, unsigned long msecs)
{
- /*
- * devices don't necessarily have an ->unplug_fn defined
- */
- if (q->unplug_fn) {
- trace_block_unplug_io(q);
- q->unplug_fn(q);
- }
+ schedule_delayed_work(&q->delay_work, msecs_to_jiffies(msecs));
}
-EXPORT_SYMBOL(blk_unplug);
+EXPORT_SYMBOL(blk_delay_queue);
/**
* blk_start_queue - restart a previously stopped queue
@@ -362,7 +271,7 @@ EXPORT_SYMBOL(blk_start_queue);
**/
void blk_stop_queue(struct request_queue *q)
{
- blk_remove_plug(q);
+ cancel_delayed_work(&q->delay_work);
queue_flag_set(QUEUE_FLAG_STOPPED, q);
}
EXPORT_SYMBOL(blk_stop_queue);
@@ -387,9 +296,9 @@ EXPORT_SYMBOL(blk_stop_queue);
*/
void blk_sync_queue(struct request_queue *q)
{
- del_timer_sync(&q->unplug_timer);
del_timer_sync(&q->timeout);
- cancel_work_sync(&q->unplug_work);
+ cancel_delayed_work_sync(&q->delay_work);
+ queue_sync_plugs(q);
}
EXPORT_SYMBOL(blk_sync_queue);
@@ -405,14 +314,9 @@ EXPORT_SYMBOL(blk_sync_queue);
*/
void __blk_run_queue(struct request_queue *q, bool force_kblockd)
{
- blk_remove_plug(q);
-
if (unlikely(blk_queue_stopped(q)))
return;
- if (elv_queue_empty(q))
- return;
-
/*
* Only recurse once to avoid overrunning the stack, let the unplug
* handling reinvoke the handler shortly if we already got there.
@@ -420,10 +324,8 @@ void __blk_run_queue(struct request_queue *q, bool force_kblockd)
if (!force_kblockd && !queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
q->request_fn(q);
queue_flag_clear(QUEUE_FLAG_REENTER, q);
- } else {
- queue_flag_set(QUEUE_FLAG_PLUGGED, q);
- kblockd_schedule_work(q, &q->unplug_work);
- }
+ } else
+ queue_delayed_work(kblockd_workqueue, &q->delay_work, 0);
}
EXPORT_SYMBOL(__blk_run_queue);
@@ -517,8 +419,6 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
if (!q)
return NULL;
- q->backing_dev_info.unplug_io_fn = blk_backing_dev_unplug;
- q->backing_dev_info.unplug_io_data = q;
q->backing_dev_info.ra_pages =
(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
@@ -538,13 +438,12 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
setup_timer(&q->backing_dev_info.laptop_mode_wb_timer,
laptop_mode_timer_fn, (unsigned long) q);
- init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
INIT_LIST_HEAD(&q->flush_queue[0]);
INIT_LIST_HEAD(&q->flush_queue[1]);
INIT_LIST_HEAD(&q->flush_data_in_flight);
- INIT_WORK(&q->unplug_work, blk_unplug_work);
+ INIT_DELAYED_WORK(&q->delay_work, blk_delay_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -639,7 +538,6 @@ blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn,
q->request_fn = rfn;
q->prep_rq_fn = NULL;
q->unprep_rq_fn = NULL;
- q->unplug_fn = generic_unplug_device;
q->queue_flags = QUEUE_FLAG_DEFAULT;
/* Override internal queue lock with supplied lock pointer */
@@ -677,6 +575,8 @@ int blk_get_queue(struct request_queue *q)
static inline void blk_free_request(struct request_queue *q, struct request *rq)
{
+ BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
+
if (rq->cmd_flags & REQ_ELVPRIV)
elv_put_request(q, rq);
mempool_free(rq, q->rq.rq_pool);
@@ -898,8 +798,8 @@ out:
}
/*
- * No available requests for this queue, unplug the device and wait for some
- * requests to become available.
+ * No available requests for this queue, wait for some requests to become
+ * available.
*
* Called with q->queue_lock held, and returns with it unlocked.
*/
@@ -920,7 +820,6 @@ static struct request *get_request_wait(struct request_queue *q, int rw_flags,
trace_block_sleeprq(q, bio, rw_flags & 1);
- __generic_unplug_device(q);
spin_unlock_irq(q->queue_lock);
io_schedule();
@@ -1042,6 +941,13 @@ void blk_requeue_request(struct request_queue *q, struct request *rq)
}
EXPORT_SYMBOL(blk_requeue_request);
+static void add_acct_request(struct request_queue *q, struct request *rq,
+ int where)
+{
+ drive_stat_acct(rq, 1);
+ __elv_add_request(q, rq, where);
+}
+
/**
* blk_insert_request - insert a special request into a request queue
* @q: request queue where request should be inserted
@@ -1084,8 +990,7 @@ void blk_insert_request(struct request_queue *q, struct request *rq,
if (blk_rq_tagged(rq))
blk_queue_end_tag(q, rq);
- drive_stat_acct(rq, 1);
- __elv_add_request(q, rq, where, 0);
+ add_acct_request(q, rq, where);
__blk_run_queue(q, false);
spin_unlock_irqrestore(q->queue_lock, flags);
}
@@ -1206,6 +1111,113 @@ void blk_add_request_payload(struct request *rq, struct page *page,
}
EXPORT_SYMBOL_GPL(blk_add_request_payload);
+static bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
+ struct bio *bio)
+{
+ const int ff = bio->bi_rw & REQ_FAILFAST_MASK;
+
+ /*
+ * Debug stuff, kill later
+ */
+ if (!rq_mergeable(req)) {
+ blk_dump_rq_flags(req, "back");
+ return false;
+ }
+
+ if (!ll_back_merge_fn(q, req, bio))
+ return false;
+
+ trace_block_bio_backmerge(q, bio);
+
+ if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
+ blk_rq_set_mixed_merge(req);
+
+ req->biotail->bi_next = bio;
+ req->biotail = bio;
+ req->__data_len += bio->bi_size;
+ req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
+
+ drive_stat_acct(req, 0);
+ return true;
+}
+
+static bool bio_attempt_front_merge(struct request_queue *q,
+ struct request *req, struct bio *bio)
+{
+ const int ff = bio->bi_rw & REQ_FAILFAST_MASK;
+ sector_t sector;
+
+ /*
+ * Debug stuff, kill later
+ */
+ if (!rq_mergeable(req)) {
+ blk_dump_rq_flags(req, "front");
+ return false;
+ }
+
+ if (!ll_front_merge_fn(q, req, bio))
+ return false;
+
+ trace_block_bio_frontmerge(q, bio);
+
+ if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
+ blk_rq_set_mixed_merge(req);
+
+ sector = bio->bi_sector;
+
+ bio->bi_next = req->bio;
+ req->bio = bio;
+
+ /*
+ * may not be valid. if the low level driver said
+ * it didn't need a bounce buffer then it better
+ * not touch req->buffer either...
+ */
+ req->buffer = bio_data(bio);
+ req->__sector = bio->bi_sector;
+ req->__data_len += bio->bi_size;
+ req->ioprio = ioprio_best(req->ioprio, bio_prio(bio));
+
+ drive_stat_acct(req, 0);
+ return true;
+}
+
+/*
+ * Attempts to merge with the plugged list in the current process. Returns
+ * true if merge was succesful, otherwise false.
+ */
+static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
+ struct bio *bio)
+{
+ struct blk_plug *plug;
+ struct request *rq;
+ bool ret = false;
+
+ plug = tsk->plug;
+ if (!plug)
+ goto out;
+
+ list_for_each_entry_reverse(rq, &plug->list, queuelist) {
+ int el_ret;
+
+ if (rq->q != q)
+ continue;
+
+ el_ret = elv_try_merge(rq, bio);
+ if (el_ret == ELEVATOR_BACK_MERGE) {
+ ret = bio_attempt_back_merge(q, rq, bio);
+ if (ret)
+ break;
+ } else if (el_ret == ELEVATOR_FRONT_MERGE) {
+ ret = bio_attempt_front_merge(q, rq, bio);
+ if (ret)
+ break;
+ }
+ }
+out:
+ return ret;
+}
+
void init_request_from_bio(struct request *req, struct bio *bio)
{
req->cpu = bio->bi_comp_cpu;
@@ -1221,26 +1233,12 @@ void init_request_from_bio(struct request *req, struct bio *bio)
blk_rq_bio_prep(req->q, req, bio);
}
-/*
- * Only disabling plugging for non-rotational devices if it does tagging
- * as well, otherwise we do need the proper merging
- */
-static inline bool queue_should_plug(struct request_queue *q)
-{
- return !(blk_queue_nonrot(q) && blk_queue_tagged(q));
-}
-
static int __make_request(struct request_queue *q, struct bio *bio)
{
- struct request *req;
- int el_ret;
- unsigned int bytes = bio->bi_size;
- const unsigned short prio = bio_prio(bio);
const bool sync = !!(bio->bi_rw & REQ_SYNC);
- const bool unplug = !!(bio->bi_rw & REQ_UNPLUG);
- const unsigned long ff = bio->bi_rw & REQ_FAILFAST_MASK;
- int where = ELEVATOR_INSERT_SORT;
- int rw_flags;
+ struct blk_plug *plug;
+ int el_ret, rw_flags, where = ELEVATOR_INSERT_SORT;
+ struct request *req;
/*
* low level driver can indicate that it wants pages above a
@@ -1249,78 +1247,36 @@ static int __make_request(struct request_queue *q, struct bio *bio)
*/
blk_queue_bounce(q, &bio);
- spin_lock_irq(q->queue_lock);
-
if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) {
+ spin_lock_irq(q->queue_lock);
where = ELEVATOR_INSERT_FLUSH;
goto get_rq;
}
- if (elv_queue_empty(q))
- goto get_rq;
-
- el_ret = elv_merge(q, &req, bio);
- switch (el_ret) {
- case ELEVATOR_BACK_MERGE:
- BUG_ON(!rq_mergeable(req));
-
- if (!ll_back_merge_fn(q, req, bio))
- break;
-
- trace_block_bio_backmerge(q, bio);
-
- if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
- blk_rq_set_mixed_merge(req);
-
- req->biotail->bi_next = bio;
- req->biotail = bio;
- req->__data_len += bytes;
- req->ioprio = ioprio_best(req->ioprio, prio);
- if (!blk_rq_cpu_valid(req))
- req->cpu = bio->bi_comp_cpu;
- drive_stat_acct(req, 0);
- elv_bio_merged(q, req, bio);
- if (!attempt_back_merge(q, req))
- elv_merged_request(q, req, el_ret);
+ /*
+ * Check if we can merge with the plugged list before grabbing
+ * any locks.
+ */
+ if (attempt_plug_merge(current, q, bio))
goto out;
- case ELEVATOR_FRONT_MERGE:
- BUG_ON(!rq_mergeable(req));
-
- if (!ll_front_merge_fn(q, req, bio))
- break;
-
- trace_block_bio_frontmerge(q, bio);
+ spin_lock_irq(q->queue_lock);
- if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) {
- blk_rq_set_mixed_merge(req);
- req->cmd_flags &= ~REQ_FAILFAST_MASK;
- req->cmd_flags |= ff;
+ el_ret = elv_merge(q, &req, bio);
+ if (el_ret == ELEVATOR_BACK_MERGE) {
+ BUG_ON(req->cmd_flags & REQ_ON_PLUG);
+ if (bio_attempt_back_merge(q, req, bio)) {
+ if (!attempt_back_merge(q, req))
+ elv_merged_request(q, req, el_ret);
+ goto out_unlock;
+ }
+ } else if (el_ret == ELEVATOR_FRONT_MERGE) {
+ BUG_ON(req->cmd_flags & REQ_ON_PLUG);
+ if (bio_attempt_front_merge(q, req, bio)) {
+ if (!attempt_front_merge(q, req))
+ elv_merged_request(q, req, el_ret);
+ goto out_unlock;
}
-
- bio->bi_next = req->bio;
- req->bio = bio;
-
- /*
- * may not be valid. if the low level driver said
- * it didn't need a bounce buffer then it better
- * not touch req->buffer either...
- */
- req->buffer = bio_data(bio);
- req->__sector = bio->bi_sector;
- req->__data_len += bytes;
- req->ioprio = ioprio_best(req->ioprio, prio);
- if (!blk_rq_cpu_valid(req))
- req->cpu = bio->bi_comp_cpu;
- drive_stat_acct(req, 0);
- elv_bio_merged(q, req, bio);
- if (!attempt_front_merge(q, req))
- elv_merged_request(q, req, el_ret);
- goto out;
-
- /* ELV_NO_MERGE: elevator says don't/can't merge. */
- default:
- ;
}
get_rq:
@@ -1347,20 +1303,35 @@ get_rq:
*/
init_request_from_bio(req, bio);
- spin_lock_irq(q->queue_lock);
if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) ||
- bio_flagged(bio, BIO_CPU_AFFINE))
- req->cpu = blk_cpu_to_group(smp_processor_id());
- if (queue_should_plug(q) && elv_queue_empty(q))
- blk_plug_device(q);
-
- /* insert the request into the elevator */
- drive_stat_acct(req, 1);
- __elv_add_request(q, req, where, 0);
+ bio_flagged(bio, BIO_CPU_AFFINE)) {
+ req->cpu = blk_cpu_to_group(get_cpu());
+ put_cpu();
+ }
+
+ plug = current->plug;
+ if (plug) {
+ if (!plug->should_sort && !list_empty(&plug->list)) {
+ struct request *__rq;
+
+ __rq = list_entry_rq(plug->list.prev);
+ if (__rq->q != q)
+ plug->should_sort = 1;
+ }
+ /*
+ * Debug flag, kill later
+ */
+ req->cmd_flags |= REQ_ON_PLUG;
+ list_add_tail(&req->queuelist, &plug->list);
+ drive_stat_acct(req, 1);
+ } else {
+ spin_lock_irq(q->queue_lock);
+ add_acct_request(q, req, where);
+ __blk_run_queue(q, false);
+out_unlock:
+ spin_unlock_irq(q->queue_lock);
+ }
out:
- if (unplug || !queue_should_plug(q))
- __generic_unplug_device(q);
- spin_unlock_irq(q->queue_lock);
return 0;
}
@@ -1763,9 +1734,7 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
*/
BUG_ON(blk_queued_rq(rq));
- drive_stat_acct(rq, 1);
- __elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 0);
-
+ add_acct_request(q, rq, ELEVATOR_INSERT_BACK);
spin_unlock_irqrestore(q->queue_lock, flags);
return 0;
@@ -2643,6 +2612,113 @@ int kblockd_schedule_work(struct request_queue *q, struct work_struct *work)
}
EXPORT_SYMBOL(kblockd_schedule_work);
+int kblockd_schedule_delayed_work(struct request_queue *q,
+ struct delayed_work *dwork, unsigned long delay)
+{
+ return queue_delayed_work(kblockd_workqueue, dwork, delay);
+}
+EXPORT_SYMBOL(kblockd_schedule_delayed_work);
+
+#define PLUG_MAGIC 0x91827364
+
+void blk_start_plug(struct blk_plug *plug)
+{
+ struct task_struct *tsk = current;
+
+ plug->magic = PLUG_MAGIC;
+ INIT_LIST_HEAD(&plug->list);
+ plug->should_sort = 0;
+
+ /*
+ * If this is a nested plug, don't actually assign it. It will be
+ * flushed on its own.
+ */
+ if (!tsk->plug) {
+ /*
+ * Store ordering should not be needed here, since a potential
+ * preempt will imply a full memory barrier
+ */
+ tsk->plug = plug;
+ }
+}
+EXPORT_SYMBOL(blk_start_plug);
+
+static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct request *rqa = container_of(a, struct request, queuelist);
+ struct request *rqb = container_of(b, struct request, queuelist);
+
+ return !(rqa->q == rqb->q);
+}
+
+static void flush_plug_list(struct blk_plug *plug)
+{
+ struct request_queue *q;
+ unsigned long flags;
+ struct request *rq;
+
+ BUG_ON(plug->magic != PLUG_MAGIC);
+
+ if (list_empty(&plug->list))
+ return;
+
+ if (plug->should_sort)
+ list_sort(NULL, &plug->list, plug_rq_cmp);
+
+ q = NULL;
+ local_irq_save(flags);
+ while (!list_empty(&plug->list)) {
+ rq = list_entry_rq(plug->list.next);
+ list_del_init(&rq->queuelist);
+ BUG_ON(!(rq->cmd_flags & REQ_ON_PLUG));
+ BUG_ON(!rq->q);
+ if (rq->q != q) {
+ if (q) {
+ __blk_run_queue(q, false);
+ spin_unlock(q->queue_lock);
+ }
+ q = rq->q;
+ spin_lock(q->queue_lock);
+ }
+ rq->cmd_flags &= ~REQ_ON_PLUG;
+
+ /*
+ * rq is already accounted, so use raw insert
+ */
+ __elv_add_request(q, rq, ELEVATOR_INSERT_SORT);
+ }
+
+ if (q) {
+ __blk_run_queue(q, false);
+ spin_unlock(q->queue_lock);
+ }
+
+ BUG_ON(!list_empty(&plug->list));
+ local_irq_restore(flags);
+}
+
+static void __blk_finish_plug(struct task_struct *tsk, struct blk_plug *plug)
+{
+ flush_plug_list(plug);
+
+ if (plug == tsk->plug)
+ tsk->plug = NULL;
+}
+
+void blk_finish_plug(struct blk_plug *plug)
+{
+ if (plug)
+ __blk_finish_plug(current, plug);
+}
+EXPORT_SYMBOL(blk_finish_plug);
+
+void __blk_flush_plug(struct task_struct *tsk, struct blk_plug *plug)
+{
+ __blk_finish_plug(tsk, plug);
+ tsk->plug = plug;
+}
+EXPORT_SYMBOL(__blk_flush_plug);
+
int __init blk_dev_init(void)
{
BUILD_BUG_ON(__REQ_NR_BITS > 8 *
diff --git a/block/blk-exec.c b/block/blk-exec.c
index cf1456a02acd..7482b7fa863b 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -54,8 +54,8 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
rq->end_io = done;
WARN_ON(irqs_disabled());
spin_lock_irq(q->queue_lock);
- __elv_add_request(q, rq, where, 1);
- __generic_unplug_device(q);
+ __elv_add_request(q, rq, where);
+ __blk_run_queue(q, false);
/* 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 0bd8c9c5d6e5..93d5fd8e51eb 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -194,7 +194,6 @@ static void flush_end_io(struct request *flush_rq, int error)
{
struct request_queue *q = flush_rq->q;
struct list_head *running = &q->flush_queue[q->flush_running_idx];
- bool was_empty = elv_queue_empty(q);
bool queued = false;
struct request *rq, *n;
@@ -218,7 +217,7 @@ static void flush_end_io(struct request *flush_rq, int error)
* from request completion path and calling directly into
* request_fn may confuse the driver. Always use kblockd.
*/
- if (queued && was_empty)
+ if (queued)
__blk_run_queue(q, true);
}
@@ -269,13 +268,12 @@ static bool blk_kick_flush(struct request_queue *q)
static void flush_data_end_io(struct request *rq, int error)
{
struct request_queue *q = rq->q;
- bool was_empty = elv_queue_empty(q);
/*
* After populating an empty queue, kick it to avoid stall. Read
* the comment in flush_end_io().
*/
- if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error) && was_empty)
+ if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error))
__blk_run_queue(q, true);
}
diff --git a/block/blk-settings.c b/block/blk-settings.c
index df649fa59ded..1fa769293597 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -164,14 +164,6 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
blk_queue_congestion_threshold(q);
q->nr_batching = BLK_BATCH_REQ;
- q->unplug_thresh = 4; /* hmm */
- q->unplug_delay = msecs_to_jiffies(3); /* 3 milliseconds */
- if (q->unplug_delay == 0)
- q->unplug_delay = 1;
-
- q->unplug_timer.function = blk_unplug_timeout;
- q->unplug_timer.data = (unsigned long)q;
-
blk_set_default_limits(&q->limits);
blk_queue_max_hw_sectors(q, BLK_SAFE_MAX_SECTORS);
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 32dd3e4b041d..37abbfc68590 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -768,6 +768,7 @@ static int throtl_dispatch(struct request_queue *q)
unsigned int nr_disp = 0;
struct bio_list bio_list_on_stack;
struct bio *bio;
+ struct blk_plug plug;
spin_lock_irq(q->queue_lock);
@@ -796,9 +797,10 @@ out:
* immediate dispatch
*/
if (nr_disp) {
+ blk_start_plug(&plug);
while((bio = bio_list_pop(&bio_list_on_stack)))
generic_make_request(bio);
- blk_unplug(q);
+ blk_finish_plug(&plug);
}
return nr_disp;
}
diff --git a/block/blk.h b/block/blk.h
index 284b500852bd..49d21af81d07 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -18,8 +18,6 @@ int blk_rq_append_bio(struct request_queue *q, struct request *rq,
void blk_dequeue_request(struct request *rq);
void __blk_queue_free_tags(struct request_queue *q);
-void blk_unplug_work(struct work_struct *work);
-void blk_unplug_timeout(unsigned long data);
void blk_rq_timed_out_timer(unsigned long data);
void blk_delete_timer(struct request *);
void blk_add_timer(struct request *);
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 9697053f80bc..c826ef81c679 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -500,13 +500,6 @@ static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
}
}
-static int cfq_queue_empty(struct request_queue *q)
-{
- struct cfq_data *cfqd = q->elevator->elevator_data;
-
- return !cfqd->rq_queued;
-}
-
/*
* Scale schedule slice based on io priority. Use the sync time slice only
* if a queue is marked sync and has sync io queued. A sync queue with async
@@ -4080,7 +4073,6 @@ static struct elevator_type iosched_cfq = {
.elevator_add_req_fn = cfq_insert_request,
.elevator_activate_req_fn = cfq_activate_request,
.elevator_deactivate_req_fn = cfq_deactivate_request,
- .elevator_queue_empty_fn = cfq_queue_empty,
.elevator_completed_req_fn = cfq_completed_request,
.elevator_former_req_fn = elv_rb_former_request,
.elevator_latter_req_fn = elv_rb_latter_request,
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index b547cbca7b23..5139c0ea1864 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -326,14 +326,6 @@ dispatch_request:
return 1;
}
-static int deadline_queue_empty(struct request_queue *q)
-{
- struct deadline_data *dd = q->elevator->elevator_data;
-
- return list_empty(&dd->fifo_list[WRITE])
- && list_empty(&dd->fifo_list[READ]);
-}
-
static void deadline_exit_queue(struct elevator_queue *e)
{
struct deadline_data *dd = e->elevator_data;
@@ -445,7 +437,6 @@ static struct elevator_type iosched_deadline = {
.elevator_merge_req_fn = deadline_merged_requests,
.elevator_dispatch_fn = deadline_dispatch_requests,
.elevator_add_req_fn = deadline_add_request,
- .elevator_queue_empty_fn = deadline_queue_empty,
.elevator_former_req_fn = elv_rb_former_request,
.elevator_latter_req_fn = elv_rb_latter_request,
.elevator_init_fn = deadline_init_queue,
diff --git a/block/elevator.c b/block/elevator.c
index fabf3675c913..542ce826b401 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -113,7 +113,7 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio)
}
EXPORT_SYMBOL(elv_rq_merge_ok);
-static inline int elv_try_merge(struct request *__rq, struct bio *bio)
+int elv_try_merge(struct request *__rq, struct bio *bio)
{
int ret = ELEVATOR_NO_MERGE;
@@ -421,6 +421,8 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
struct list_head *entry;
int stop_flags;
+ BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
+
if (q->last_merge == rq)
q->last_merge = NULL;
@@ -617,21 +619,12 @@ void elv_quiesce_end(struct request_queue *q)
void elv_insert(struct request_queue *q, struct request *rq, int where)
{
- int unplug_it = 1;
-
trace_block_rq_insert(q, rq);
rq->q = q;
switch (where) {
case ELEVATOR_INSERT_REQUEUE:
- /*
- * Most requeues happen because of a busy condition,
- * don't force unplug of the queue for that case.
- * Clear unplug_it and fall through.
- */
- unplug_it = 0;
-
case ELEVATOR_INSERT_FRONT:
rq->cmd_flags |= REQ_SOFTBARRIER;
list_add(&rq->queuelist, &q->queue_head);
@@ -677,25 +670,17 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
rq->cmd_flags |= REQ_SOFTBARRIER;
blk_insert_flush(rq);
break;
-
default:
printk(KERN_ERR "%s: bad insertion point %d\n",
__func__, where);
BUG();
}
-
- if (unplug_it && blk_queue_plugged(q)) {
- int nrq = q->rq.count[BLK_RW_SYNC] + q->rq.count[BLK_RW_ASYNC]
- - queue_in_flight(q);
-
- if (nrq >= q->unplug_thresh)
- __generic_unplug_device(q);
- }
}
-void __elv_add_request(struct request_queue *q, struct request *rq, int where,
- int plug)
+void __elv_add_request(struct request_queue *q, struct request *rq, int where)
{
+ BUG_ON(rq->cmd_flags & REQ_ON_PLUG);
+
if (rq->cmd_flags & REQ_SOFTBARRIER) {
/* barriers are scheduling boundary, update end_sector */
if (rq->cmd_type == REQ_TYPE_FS ||
@@ -707,38 +692,20 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where,
where == ELEVATOR_INSERT_SORT)
where = ELEVATOR_INSERT_BACK;
- if (plug)
- blk_plug_device(q);
-
elv_insert(q, rq, where);
}
EXPORT_SYMBOL(__elv_add_request);
-void elv_add_request(struct request_queue *q, struct request *rq, int where,
- int plug)
+void elv_add_request(struct request_queue *q, struct request *rq, int where)
{
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
- __elv_add_request(q, rq, where, plug);
+ __elv_add_request(q, rq, where);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(elv_add_request);
-int elv_queue_empty(struct request_queue *q)
-{
- struct elevator_queue *e = q->elevator;
-
- if (!list_empty(&q->queue_head))
- return 0;
-
- if (e->ops->elevator_queue_empty_fn)
- return e->ops->elevator_queue_empty_fn(q);
-
- return 1;
-}
-EXPORT_SYMBOL(elv_queue_empty);
-
struct request *elv_latter_request(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;
diff --git a/block/noop-iosched.c b/block/noop-iosched.c
index 232c4b38cd37..06389e9ef96d 100644
--- a/block/noop-iosched.c
+++ b/block/noop-iosched.c
@@ -39,13 +39,6 @@ static void noop_add_request(struct request_queue *q, struct request *rq)
list_add_tail(&rq->queuelist, &nd->queue);
}
-static int noop_queue_empty(struct request_queue *q)
-{
- struct noop_data *nd = q->elevator->elevator_data;
-
- return list_empty(&nd->queue);
-}
-
static struct request *
noop_former_request(struct request_queue *q, struct request *rq)
{
@@ -90,7 +83,6 @@ static struct elevator_type elevator_noop = {
.elevator_merge_req_fn = noop_merged_requests,
.elevator_dispatch_fn = noop_dispatch,
.elevator_add_req_fn = noop_add_request,
- .elevator_queue_empty_fn = noop_queue_empty,
.elevator_former_req_fn = noop_former_request,
.elevator_latter_req_fn = noop_latter_request,
.elevator_init_fn = noop_init_queue,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 10:17:17 +0000