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Commit b8aca35a authored by Jens Axboe's avatar Jens Axboe Committed by Jens Axboe
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[PATCH] deadline-iosched: migrate to using the elevator rb functions 

This removes the rbtree handling from deadline.
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent 21183b07
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Showing with 34 additions and 136 deletions
block/deadline-iosched.c
View file @ b8aca35a
......@@ -57,12 +57,6 @@ struct deadline_data {
* pre-request data.
*/
struct deadline_rq {
/*
* rbtree index, key is the starting offset
*/
struct rb_node rb_node;
sector_t rb_key;
struct request *request;
/*
......@@ -78,108 +72,38 @@ static kmem_cache_t *drq_pool;
#define RQ_DATA(rq) ((struct deadline_rq *) (rq)->elevator_private)
/*
* rb tree support functions
*/
#define rb_entry_drq(node) rb_entry((node), struct deadline_rq, rb_node)
#define DRQ_RB_ROOT(dd, drq) (&(dd)->sort_list[rq_data_dir((drq)->request)])
#define rq_rb_key(rq) (rq)->sector
static struct deadline_rq *
__deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
{
struct rb_node **p = &DRQ_RB_ROOT(dd, drq)->rb_node;
struct rb_node *parent = NULL;
struct deadline_rq *__drq;
while (*p) {
parent = *p;
__drq = rb_entry_drq(parent);
if (drq->rb_key < __drq->rb_key)
p = &(*p)->rb_left;
else if (drq->rb_key > __drq->rb_key)
p = &(*p)->rb_right;
else
return __drq;
}
rb_link_node(&drq->rb_node, parent, p);
return NULL;
}
#define RQ_RB_ROOT(dd, rq) (&(dd)->sort_list[rq_data_dir((rq))])
#define DRQ_RB_ROOT(dd, drq) RQ_RB_ROOT((drq)->request)
static void
deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
deadline_add_drq_rb(struct deadline_data *dd, struct request *rq)
{
struct deadline_rq *__alias;
drq->rb_key = rq_rb_key(drq->request);
struct rb_root *root = RQ_RB_ROOT(dd, rq);
struct request *__alias;
retry:
__alias = __deadline_add_drq_rb(dd, drq);
if (!__alias) {
rb_insert_color(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
return;
__alias = elv_rb_add(root, rq);
if (unlikely(__alias)) {
deadline_move_request(dd, RQ_DATA(__alias));
goto retry;
}
deadline_move_request(dd, __alias);
goto retry;
}
static inline void
deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
{
const int data_dir = rq_data_dir(drq->request);
struct request *rq = drq->request;
const int data_dir = rq_data_dir(rq);
if (dd->next_drq[data_dir] == drq) {
struct rb_node *rbnext = rb_next(&drq->rb_node);
struct rb_node *rbnext = rb_next(&rq->rb_node);
dd->next_drq[data_dir] = NULL;
if (rbnext)
dd->next_drq[data_dir] = rb_entry_drq(rbnext);
}
BUG_ON(!RB_EMPTY_NODE(&drq->rb_node));
rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
RB_CLEAR_NODE(&drq->rb_node);
}
static struct request *
deadline_find_drq_rb(struct deadline_data *dd, sector_t sector, int data_dir)
{
struct rb_node *n = dd->sort_list[data_dir].rb_node;
struct deadline_rq *drq;
while (n) {
drq = rb_entry_drq(n);
if (sector < drq->rb_key)
n = n->rb_left;
else if (sector > drq->rb_key)
n = n->rb_right;
else
return drq->request;
dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
}
return NULL;
}
/*
* deadline_find_first_drq finds the first (lowest sector numbered) request
* for the specified data_dir. Used to sweep back to the start of the disk
* (1-way elevator) after we process the last (highest sector) request.
*/
static struct deadline_rq *
deadline_find_first_drq(struct deadline_data *dd, int data_dir)
{
struct rb_node *n = dd->sort_list[data_dir].rb_node;
for (;;) {
if (n->rb_left == NULL)
return rb_entry_drq(n);
n = n->rb_left;
}
elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
}
/*
......@@ -192,7 +116,7 @@ deadline_add_request(struct request_queue *q, struct request *rq)
struct deadline_rq *drq = RQ_DATA(rq);
const int data_dir = rq_data_dir(drq->request);
deadline_add_drq_rb(dd, drq);
deadline_add_drq_rb(dd, rq);
/*
* set expire time (only used for reads) and add to fifo list
......@@ -224,11 +148,11 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
* check for front merge
*/
if (dd->front_merges) {
sector_t rb_key = bio->bi_sector + bio_sectors(bio);
sector_t sector = bio->bi_sector + bio_sectors(bio);
__rq = deadline_find_drq_rb(dd, rb_key, bio_data_dir(bio));
__rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
if (__rq) {
BUG_ON(rb_key != rq_rb_key(__rq));
BUG_ON(sector != __rq->sector);
if (elv_rq_merge_ok(__rq, bio)) {
ret = ELEVATOR_FRONT_MERGE;
......@@ -243,17 +167,17 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
return ret;
}
static void deadline_merged_request(request_queue_t *q, struct request *req)
static void deadline_merged_request(request_queue_t *q, struct request *req,
int type)
{
struct deadline_data *dd = q->elevator->elevator_data;
struct deadline_rq *drq = RQ_DATA(req);
/*
* if the merge was a front merge, we need to reposition request
*/
if (rq_rb_key(req) != drq->rb_key) {
deadline_del_drq_rb(dd, drq);
deadline_add_drq_rb(dd, drq);
if (type == ELEVATOR_FRONT_MERGE) {
elv_rb_del(RQ_RB_ROOT(dd, req), req);
deadline_add_drq_rb(dd, req);
}
}
......@@ -261,18 +185,12 @@ static void
deadline_merged_requests(request_queue_t *q, struct request *req,
struct request *next)
{
struct deadline_data *dd = q->elevator->elevator_data;
struct deadline_rq *drq = RQ_DATA(req);
struct deadline_rq *dnext = RQ_DATA(next);
BUG_ON(!drq);
BUG_ON(!dnext);
if (rq_rb_key(req) != drq->rb_key) {
deadline_del_drq_rb(dd, drq);
deadline_add_drq_rb(dd, drq);
}
/*
* if dnext expires before drq, assign its expire time to drq
* and move into dnext position (dnext will be deleted) in fifo
......@@ -308,14 +226,15 @@ deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq)
static void
deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq)
{
const int data_dir = rq_data_dir(drq->request);
struct rb_node *rbnext = rb_next(&drq->rb_node);
struct request *rq = drq->request;
const int data_dir = rq_data_dir(rq);
struct rb_node *rbnext = rb_next(&rq->rb_node);
dd->next_drq[READ] = NULL;
dd->next_drq[WRITE] = NULL;
if (rbnext)
dd->next_drq[data_dir] = rb_entry_drq(rbnext);
dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));
dd->last_sector = drq->request->sector + drq->request->nr_sectors;
......@@ -426,13 +345,17 @@ static int deadline_dispatch_requests(request_queue_t *q, int force)
*/
drq = dd->next_drq[data_dir];
} else {
struct rb_node *n;
/*
* The last req was the other direction or we have run out of
* higher-sectored requests. Go back to the lowest sectored
* request (1 way elevator) and start a new batch.
*/
dd->batching = 0;
drq = deadline_find_first_drq(dd, data_dir);
n = rb_first(&dd->sort_list[data_dir]);
if (n)
drq = RQ_DATA(rb_entry_rq(n));
}
dispatch_request:
......@@ -453,30 +376,6 @@ static int deadline_queue_empty(request_queue_t *q)
&& list_empty(&dd->fifo_list[READ]);
}
static struct request *
deadline_former_request(request_queue_t *q, struct request *rq)
{
struct deadline_rq *drq = RQ_DATA(rq);
struct rb_node *rbprev = rb_prev(&drq->rb_node);
if (rbprev)
return rb_entry_drq(rbprev)->request;
return NULL;
}
static struct request *
deadline_latter_request(request_queue_t *q, struct request *rq)
{
struct deadline_rq *drq = RQ_DATA(rq);
struct rb_node *rbnext = rb_next(&drq->rb_node);
if (rbnext)
return rb_entry_drq(rbnext)->request;
return NULL;
}
static void deadline_exit_queue(elevator_t *e)
{
struct deadline_data *dd = e->elevator_data;
......@@ -542,7 +441,6 @@ deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
drq = mempool_alloc(dd->drq_pool, gfp_mask);
if (drq) {
memset(drq, 0, sizeof(*drq));
RB_CLEAR_NODE(&drq->rb_node);
drq->request = rq;
INIT_LIST_HEAD(&drq->fifo);
......@@ -633,8 +531,8 @@ static struct elevator_type iosched_deadline = {
.elevator_dispatch_fn = deadline_dispatch_requests,
.elevator_add_req_fn = deadline_add_request,
.elevator_queue_empty_fn = deadline_queue_empty,
.elevator_former_req_fn = deadline_former_request,
.elevator_latter_req_fn = deadline_latter_request,
.elevator_former_req_fn = elv_rb_former_request,
.elevator_latter_req_fn = elv_rb_latter_request,
.elevator_set_req_fn = deadline_set_request,
.elevator_put_req_fn = deadline_put_request,
.elevator_init_fn = deadline_init_queue,
......
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