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authorTejun Heo <tj@kernel.org>2012-06-05 07:40:58 +0400
committerJens Axboe <axboe@kernel.dk>2012-06-25 13:53:51 +0400
commit8a5ecdd42862bf87ceab00bf2a15d7eabf58c02d (patch)
tree36ff209f0655c5da9cfb7c5c6f6e9b9786841201
parentb1208b56f31408f7d8381ff5d08e970aa5ee761c (diff)
downloadlinux-8a5ecdd42862bf87ceab00bf2a15d7eabf58c02d.tar.xz
block: add q->nr_rqs[] and move q->rq.elvpriv to q->nr_rqs_elvpriv
Add q->nr_rqs[] which currently behaves the same as q->rq.count[] and move q->rq.elvpriv to q->nr_rqs_elvpriv. blk_drain_queue() is updated to use q->nr_rqs[] instead of q->rq.count[]. These counters separates queue-wide request statistics from the request list and allow implementation of per-queue request allocation. While at it, properly indent fields of struct request_list. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-core.c13
-rw-r--r--include/linux/blkdev.h11
2 files changed, 13 insertions, 11 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 71894e143b91..a2648153691f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -387,7 +387,7 @@ void blk_drain_queue(struct request_queue *q, bool drain_all)
if (!list_empty(&q->queue_head) && q->request_fn)
__blk_run_queue(q);
- drain |= q->rq.elvpriv;
+ drain |= q->nr_rqs_elvpriv;
/*
* Unfortunately, requests are queued at and tracked from
@@ -397,7 +397,7 @@ void blk_drain_queue(struct request_queue *q, bool drain_all)
if (drain_all) {
drain |= !list_empty(&q->queue_head);
for (i = 0; i < 2; i++) {
- drain |= q->rq.count[i];
+ drain |= q->nr_rqs[i];
drain |= q->in_flight[i];
drain |= !list_empty(&q->flush_queue[i]);
}
@@ -526,7 +526,6 @@ static int blk_init_free_list(struct request_queue *q)
rl->count[BLK_RW_SYNC] = rl->count[BLK_RW_ASYNC] = 0;
rl->starved[BLK_RW_SYNC] = rl->starved[BLK_RW_ASYNC] = 0;
- rl->elvpriv = 0;
init_waitqueue_head(&rl->wait[BLK_RW_SYNC]);
init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]);
@@ -791,9 +790,10 @@ static void freed_request(struct request_queue *q, unsigned int flags)
struct request_list *rl = &q->rq;
int sync = rw_is_sync(flags);
+ q->nr_rqs[sync]--;
rl->count[sync]--;
if (flags & REQ_ELVPRIV)
- rl->elvpriv--;
+ q->nr_rqs_elvpriv--;
__freed_request(q, sync);
@@ -902,6 +902,7 @@ static struct request *__get_request(struct request_queue *q, int rw_flags,
if (rl->count[is_sync] >= (3 * q->nr_requests / 2))
return NULL;
+ q->nr_rqs[is_sync]++;
rl->count[is_sync]++;
rl->starved[is_sync] = 0;
@@ -917,7 +918,7 @@ static struct request *__get_request(struct request_queue *q, int rw_flags,
*/
if (blk_rq_should_init_elevator(bio) && !blk_queue_bypass(q)) {
rw_flags |= REQ_ELVPRIV;
- rl->elvpriv++;
+ q->nr_rqs_elvpriv++;
if (et->icq_cache && ioc)
icq = ioc_lookup_icq(ioc, q);
}
@@ -978,7 +979,7 @@ fail_elvpriv:
rq->elv.icq = NULL;
spin_lock_irq(q->queue_lock);
- rl->elvpriv--;
+ q->nr_rqs_elvpriv--;
spin_unlock_irq(q->queue_lock);
goto out;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 07954b05b86c..7e44ed93f84b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -51,11 +51,10 @@ struct request_list {
* count[], starved[], and wait[] are indexed by
* BLK_RW_SYNC/BLK_RW_ASYNC
*/
- int count[2];
- int starved[2];
- int elvpriv;
- mempool_t *rq_pool;
- wait_queue_head_t wait[2];
+ int count[2];
+ int starved[2];
+ mempool_t *rq_pool;
+ wait_queue_head_t wait[2];
};
/*
@@ -282,6 +281,8 @@ struct request_queue {
struct list_head queue_head;
struct request *last_merge;
struct elevator_queue *elevator;
+ int nr_rqs[2]; /* # allocated [a]sync rqs */
+ int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
/*
* the queue request freelist, one for reads and one for writes