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

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
......@@ -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);
......
......@@ -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);
......
......@@ -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;
}
......
......@@ -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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