diff options
author | Jens Axboe <jaxboe@fusionio.com> | 2011-03-10 07:52:07 (GMT) |
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committer | Jens Axboe <jaxboe@fusionio.com> | 2011-03-10 07:52:07 (GMT) |
commit | 7eaceaccab5f40bbfda044629a6298616aeaed50 (patch) | |
tree | 33954d12f63e25a47eb6d86ef3d3d0a5e62bf752 /block/blk-core.c | |
parent | 73c101011926c5832e6e141682180c4debe2cf45 (diff) | |
download | linux-fsl-qoriq-7eaceaccab5f40bbfda044629a6298616aeaed50.tar.xz |
block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/blk-core.c')
-rw-r--r-- | block/blk-core.c | 173 |
1 files changed, 20 insertions, 153 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 6efb55c..82a4589 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -198,6 +198,19 @@ void blk_dump_rq_flags(struct request *rq, char *msg) } EXPORT_SYMBOL(blk_dump_rq_flags); +/* + * 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) +{ + /* + * If the current process is plugged and has barriers submitted, + * we will livelock if we don't unplug first. + */ + blk_flush_plug(current); +} + static void blk_delay_work(struct work_struct *work) { struct request_queue *q; @@ -224,137 +237,6 @@ void blk_delay_queue(struct request_queue *q, unsigned long msecs) } EXPORT_SYMBOL(blk_delay_queue); -/* - * "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) -{ - WARN_ON(!irqs_disabled()); - - /* - * don't plug a stopped queue, it must be paired with blk_start_queue() - * which will restart the queueing - */ - 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; -} -EXPORT_SYMBOL(blk_remove_plug); - -/* - * remove the plug and let it rip.. - */ -void __generic_unplug_device(struct request_queue *q) -{ - if (unlikely(blk_queue_stopped(q))) - return; - if (!blk_remove_plug(q) && !blk_queue_nonrot(q)) - return; - - q->request_fn(q); -} - -/** - * generic_unplug_device - fire a request queue - * @q: The &struct request_queue in question - * - * 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) -{ - /* - * devices don't necessarily have an ->unplug_fn defined - */ - if (q->unplug_fn) { - trace_block_unplug_io(q); - q->unplug_fn(q); - } -} -EXPORT_SYMBOL(blk_unplug); - /** * blk_start_queue - restart a previously stopped queue * @q: The &struct request_queue in question @@ -389,7 +271,6 @@ 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); } @@ -411,11 +292,10 @@ 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); throtl_shutdown_timer_wq(q); cancel_delayed_work_sync(&q->delay_work); + queue_sync_plugs(q); } EXPORT_SYMBOL(blk_sync_queue); @@ -430,14 +310,9 @@ EXPORT_SYMBOL(blk_sync_queue); */ void __blk_run_queue(struct request_queue *q) { - 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. @@ -445,10 +320,8 @@ void __blk_run_queue(struct request_queue *q) if (!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); @@ -535,8 +408,6 @@ 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; @@ -556,13 +427,11 @@ 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); @@ -652,7 +521,6 @@ 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; q->queue_lock = lock; @@ -910,8 +778,8 @@ 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. */ @@ -932,7 +800,6 @@ 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(); @@ -1058,7 +925,7 @@ 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, 0); + __elv_add_request(q, rq, where); } /** @@ -2798,7 +2665,7 @@ static void flush_plug_list(struct blk_plug *plug) /* * rq is already accounted, so use raw insert */ - __elv_add_request(q, rq, ELEVATOR_INSERT_SORT, 0); + __elv_add_request(q, rq, ELEVATOR_INSERT_SORT); } if (q) { |