diff options
author | Tejun Heo <tj@kernel.org> | 2009-04-23 11:05:17 +0900 |
---|---|---|
committer | Jens Axboe <jens.axboe@oracle.com> | 2009-04-28 07:37:33 +0200 |
commit | a538cd03be6f363d039daa94199c28cfbd508455 (patch) | |
tree | 47d327e3339f5f07c4f4386537fab526310344a7 /block | |
parent | db2dbb12dc47a50c7a4c5678f526014063e486f6 (diff) | |
download | kernel_samsung_smdk4412-a538cd03be6f363d039daa94199c28cfbd508455.zip kernel_samsung_smdk4412-a538cd03be6f363d039daa94199c28cfbd508455.tar.gz kernel_samsung_smdk4412-a538cd03be6f363d039daa94199c28cfbd508455.tar.bz2 |
block: merge blk_invoke_request_fn() into __blk_run_queue()
__blk_run_queue wraps blk_invoke_request_fn() such that it
additionally removes plug and bails out early if the queue is empty.
Both extra operations have their own pending mechanisms and don't
cause any harm correctness-wise when they are done superflously.
The only user of blk_invoke_request_fn() being blk_start_queue(),
there isn't much reason to keep both functions around. Merge
blk_invoke_request_fn() into __blk_run_queue() and make
blk_start_queue() use __blk_run_queue() instead.
[ Impact: merge two subtly different internal functions ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'block')
-rw-r--r-- | block/blk-core.c | 35 |
1 files changed, 14 insertions, 21 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 41bc0ff..02f53bc 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -333,24 +333,6 @@ void blk_unplug(struct request_queue *q) } EXPORT_SYMBOL(blk_unplug); -static void blk_invoke_request_fn(struct request_queue *q) -{ - if (unlikely(blk_queue_stopped(q))) - return; - - /* - * one level of recursion is ok and is much faster than kicking - * the unplug handling - */ - 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); - } -} - /** * blk_start_queue - restart a previously stopped queue * @q: The &struct request_queue in question @@ -365,7 +347,7 @@ void blk_start_queue(struct request_queue *q) WARN_ON(!irqs_disabled()); queue_flag_clear(QUEUE_FLAG_STOPPED, q); - blk_invoke_request_fn(q); + __blk_run_queue(q); } EXPORT_SYMBOL(blk_start_queue); @@ -425,12 +407,23 @@ 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. */ - if (!elv_queue_empty(q)) - blk_invoke_request_fn(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); + } } EXPORT_SYMBOL(__blk_run_queue); |