Commit a612fddf authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq 



Most of icq management is about to be moved out of cfq into blk-ioc.
This patch prepares for it.

* Move cfqd->icq_list to request_queue->icq_list

* Make request explicitly point to icq instead of through elevator
  private data.  ->elevator_private[3] is replaced with sub struct elv
  which contains icq pointer and priv[2].  cfq is updated accordingly.

* Meaningless clearing of ->elevator_private[0] removed from
  elv_set_request().  At that point in code, the field was guaranteed
  to be %NULL anyway.

This patch doesn't introduce any functional change.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c5869807

block/blk-core.c

+1 −0
Original line number Diff line number Diff line
@@ -497,6 +497,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) 
		    laptop_mode_timer_fn, (unsigned long) q);

	setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);

	INIT_LIST_HEAD(&q->timeout_list);

	INIT_LIST_HEAD(&q->icq_list);

	INIT_LIST_HEAD(&q->flush_queue[0]);

	INIT_LIST_HEAD(&q->flush_queue[1]);

	INIT_LIST_HEAD(&q->flush_data_in_flight);

block/cfq-iosched.c

+11 −17
Original line number Diff line number Diff line
@@ -54,9 +54,9 @@ static const int cfq_hist_divisor = 4; 
#define CFQQ_SECT_THR_NONROT	(sector_t)(2 * 32)

#define CFQQ_SEEKY(cfqq)	(hweight32(cfqq->seek_history) > 32/8)



#define RQ_CIC(rq)		icq_to_cic((rq)->elevator_private[0])

#define RQ_CFQQ(rq)		(struct cfq_queue *) ((rq)->elevator_private[1])

#define RQ_CFQG(rq)		(struct cfq_group *) ((rq)->elevator_private[2])

#define RQ_CIC(rq)		icq_to_cic((rq)->elv.icq)

#define RQ_CFQQ(rq)		(struct cfq_queue *) ((rq)->elv.priv[0])

#define RQ_CFQG(rq)		(struct cfq_group *) ((rq)->elv.priv[1])



static struct kmem_cache *cfq_pool;

static struct kmem_cache *cfq_icq_pool;
@@ -297,8 +297,6 @@ struct cfq_data { 
	unsigned int cfq_group_idle;

	unsigned int cfq_latency;



	struct list_head icq_list;



	/*

	 * Fallback dummy cfqq for extreme OOM conditions

	 */
@@ -3053,7 +3051,7 @@ static int cfq_create_cic(struct cfq_data *cfqd, gfp_t gfp_mask) 
	ret = radix_tree_insert(&ioc->icq_tree, q->id, icq);

	if (likely(!ret)) {

		hlist_add_head(&icq->ioc_node, &ioc->icq_list);

		list_add(&icq->q_node, &cfqd->icq_list);

		list_add(&icq->q_node, &q->icq_list);

		icq = NULL;

	} else if (ret == -EEXIST) {

		/* someone else already did it */
@@ -3605,12 +3603,10 @@ static void cfq_put_request(struct request *rq) 


		put_io_context(RQ_CIC(rq)->icq.ioc, cfqq->cfqd->queue);



		rq->elevator_private[0] = NULL;

		rq->elevator_private[1] = NULL;



		/* Put down rq reference on cfqg */

		cfq_put_cfqg(RQ_CFQG(rq));

		rq->elevator_private[2] = NULL;

		rq->elv.priv[0] = NULL;

		rq->elv.priv[1] = NULL;



		cfq_put_queue(cfqq);

	}
@@ -3696,9 +3692,9 @@ new_queue: 
	cfqq->allocated[rw]++;



	cfqq->ref++;

	rq->elevator_private[0] = &cic->icq;

	rq->elevator_private[1] = cfqq;

	rq->elevator_private[2] = cfq_ref_get_cfqg(cfqq->cfqg);

	rq->elv.icq = &cic->icq;

	rq->elv.priv[0] = cfqq;

	rq->elv.priv[1] = cfq_ref_get_cfqg(cfqq->cfqg);

	spin_unlock_irq(q->queue_lock);

	return 0;
@@ -3810,8 +3806,8 @@ static void cfq_exit_queue(struct elevator_queue *e) 
	if (cfqd->active_queue)

		__cfq_slice_expired(cfqd, cfqd->active_queue, 0);



	while (!list_empty(&cfqd->icq_list)) {

		struct io_cq *icq = list_entry(cfqd->icq_list.next,

	while (!list_empty(&q->icq_list)) {

		struct io_cq *icq = list_entry(q->icq_list.next,

					       struct io_cq, q_node);

		struct io_context *ioc = icq->ioc;
@@ -3922,8 +3918,6 @@ static void *cfq_init_queue(struct request_queue *q) 
	cfqd->oom_cfqq.ref++;

	cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);



	INIT_LIST_HEAD(&cfqd->icq_list);



	cfqd->queue = q;



	init_timer(&cfqd->idle_slice_timer);

block/elevator.c

+0 −2
Original line number Diff line number Diff line
@@ -745,8 +745,6 @@ int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) 


	if (e->type->ops.elevator_set_req_fn)

		return e->type->ops.elevator_set_req_fn(q, rq, gfp_mask);



	rq->elevator_private[0] = NULL;

	return 0;

}

include/linux/blkdev.h

+8 −2
Original line number Diff line number Diff line
@@ -111,10 +111,14 @@ struct request { 
	 * Three pointers are available for the IO schedulers, if they need

	 * more they have to dynamically allocate it.  Flush requests are

	 * never put on the IO scheduler. So let the flush fields share

	 * space with the three elevator_private pointers.

	 * space with the elevator data.

	 */

	union {

		void *elevator_private[3];

		struct {

			struct io_cq		*icq;

			void			*priv[2];

		} elv;



		struct {

			unsigned int		seq;

			struct list_head	list;
@@ -357,6 +361,8 @@ struct request_queue { 
	struct timer_list	timeout;

	struct list_head	timeout_list;



	struct list_head	icq_list;



	struct queue_limits	limits;



	/*

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