[PATCH] block: Remove the extra check in queue_requests_store.

[PATCH] block: Remove the extra check in queue_requests_store.

[Tao Ma]

From: Tao Ma <boyu.mt@taobao.com>

In queue_requests_store, the code looks like
	if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
		blk_set_queue_full(q, BLK_RW_SYNC);
	} else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
		blk_clear_queue_full(q, BLK_RW_SYNC);
		wake_up(&rl->wait[BLK_RW_SYNC]);
	}
If we don't satify the situation of "if", we can get that
rl->count[BLK_RW_SYNC} < q->nr_quests. It is the same as
rl->count[BLK_RW_SYNC]+1 <= q->nr_requests.
All the "else" should satisfy the "else if" check so it isn't
needed actually.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
---
 block/blk-sysfs.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 6d73512..644e2d3 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -66,14 +66,14 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
 
 	if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
 		blk_set_queue_full(q, BLK_RW_SYNC);
-	} else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
+	} else {
 		blk_clear_queue_full(q, BLK_RW_SYNC);
 		wake_up(&rl->wait[BLK_RW_SYNC]);
 	}
 
 	if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
 		blk_set_queue_full(q, BLK_RW_ASYNC);
-	} else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
+	} else {
 		blk_clear_queue_full(q, BLK_RW_ASYNC);
 		wake_up(&rl->wait[BLK_RW_ASYNC]);
 	}
-- 
1.6.3.GIT

Re: [PATCH] block: Remove the extra check in queue_requests_store.

[Jens Axboe]

On 2011-04-19 10:26, Tao Ma wrote:
> From: Tao Ma <boyu.mt@taobao.com>
> 
> In queue_requests_store, the code looks like
> 	if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
> 		blk_set_queue_full(q, BLK_RW_SYNC);
> 	} else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
> 		blk_clear_queue_full(q, BLK_RW_SYNC);
> 		wake_up(&rl->wait[BLK_RW_SYNC]);
> 	}
> If we don't satify the situation of "if", we can get that
> rl->count[BLK_RW_SYNC} < q->nr_quests. It is the same as
> rl->count[BLK_RW_SYNC]+1 <= q->nr_requests.
> All the "else" should satisfy the "else if" check so it isn't
> needed actually.

Thanks, applied.

-- 
Jens Axboe