X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=block%2Fdeadline-iosched.c;h=b547cbca7b23a55dd9d1f0b444bed07d297fc646;hp=b7c5b34cb7b43b4688b3f4bbda5951726bbb008a;hb=dc7a08166f3a5f23e79e839a8a88849bd3397c32;hpb=0fe23479577124bd2687e6783e39fa0fa4c28005 diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index b7c5b34..b547cbc 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c @@ -33,7 +33,7 @@ struct deadline_data { */ struct rb_root sort_list[2]; struct list_head fifo_list[2]; - + /* * next in sort order. read, write or both are NULL */ @@ -53,20 +53,34 @@ struct deadline_data { static void deadline_move_request(struct deadline_data *, struct request *); -#define RQ_RB_ROOT(dd, rq) (&(dd)->sort_list[rq_data_dir((rq))]) +static inline struct rb_root * +deadline_rb_root(struct deadline_data *dd, struct request *rq) +{ + return &dd->sort_list[rq_data_dir(rq)]; +} + +/* + * get the request after `rq' in sector-sorted order + */ +static inline struct request * +deadline_latter_request(struct request *rq) +{ + struct rb_node *node = rb_next(&rq->rb_node); + + if (node) + return rb_entry_rq(node); + + return NULL; +} static void deadline_add_rq_rb(struct deadline_data *dd, struct request *rq) { - struct rb_root *root = RQ_RB_ROOT(dd, rq); + struct rb_root *root = deadline_rb_root(dd, rq); struct request *__alias; -retry: - __alias = elv_rb_add(root, rq); - if (unlikely(__alias)) { + while (unlikely(__alias = elv_rb_add(root, rq))) deadline_move_request(dd, __alias); - goto retry; - } } static inline void @@ -74,15 +88,10 @@ deadline_del_rq_rb(struct deadline_data *dd, struct request *rq) { const int data_dir = rq_data_dir(rq); - if (dd->next_rq[data_dir] == rq) { - struct rb_node *rbnext = rb_next(&rq->rb_node); + if (dd->next_rq[data_dir] == rq) + dd->next_rq[data_dir] = deadline_latter_request(rq); - dd->next_rq[data_dir] = NULL; - if (rbnext) - dd->next_rq[data_dir] = rb_entry_rq(rbnext); - } - - elv_rb_del(RQ_RB_ROOT(dd, rq), rq); + elv_rb_del(deadline_rb_root(dd, rq), rq); } /* @@ -97,7 +106,7 @@ deadline_add_request(struct request_queue *q, struct request *rq) deadline_add_rq_rb(dd, rq); /* - * set expire time (only used for reads) and add to fifo list + * set expire time and add to fifo list */ rq_set_fifo_time(rq, jiffies + dd->fifo_expire[data_dir]); list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]); @@ -106,7 +115,7 @@ deadline_add_request(struct request_queue *q, struct request *rq) /* * remove rq from rbtree and fifo. */ -static void deadline_remove_request(request_queue_t *q, struct request *rq) +static void deadline_remove_request(struct request_queue *q, struct request *rq) { struct deadline_data *dd = q->elevator->elevator_data; @@ -115,7 +124,7 @@ static void deadline_remove_request(request_queue_t *q, struct request *rq) } static int -deadline_merge(request_queue_t *q, struct request **req, struct bio *bio) +deadline_merge(struct request_queue *q, struct request **req, struct bio *bio) { struct deadline_data *dd = q->elevator->elevator_data; struct request *__rq; @@ -129,7 +138,7 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio) __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector); if (__rq) { - BUG_ON(sector != __rq->sector); + BUG_ON(sector != blk_rq_pos(__rq)); if (elv_rq_merge_ok(__rq, bio)) { ret = ELEVATOR_FRONT_MERGE; @@ -144,8 +153,8 @@ out: return ret; } -static void deadline_merged_request(request_queue_t *q, struct request *req, - int type) +static void deadline_merged_request(struct request_queue *q, + struct request *req, int type) { struct deadline_data *dd = q->elevator->elevator_data; @@ -153,13 +162,13 @@ static void deadline_merged_request(request_queue_t *q, struct request *req, * if the merge was a front merge, we need to reposition request */ if (type == ELEVATOR_FRONT_MERGE) { - elv_rb_del(RQ_RB_ROOT(dd, req), req); + elv_rb_del(deadline_rb_root(dd, req), req); deadline_add_rq_rb(dd, req); } } static void -deadline_merged_requests(request_queue_t *q, struct request *req, +deadline_merged_requests(struct request_queue *q, struct request *req, struct request *next) { /* @@ -185,7 +194,7 @@ deadline_merged_requests(request_queue_t *q, struct request *req, static inline void deadline_move_to_dispatch(struct deadline_data *dd, struct request *rq) { - request_queue_t *q = rq->q; + struct request_queue *q = rq->q; deadline_remove_request(q, rq); elv_dispatch_add_tail(q, rq); @@ -198,15 +207,12 @@ static void deadline_move_request(struct deadline_data *dd, struct request *rq) { const int data_dir = rq_data_dir(rq); - struct rb_node *rbnext = rb_next(&rq->rb_node); dd->next_rq[READ] = NULL; dd->next_rq[WRITE] = NULL; + dd->next_rq[data_dir] = deadline_latter_request(rq); - if (rbnext) - dd->next_rq[data_dir] = rb_entry_rq(rbnext); - - dd->last_sector = rq->sector + rq->nr_sectors; + dd->last_sector = rq_end_sector(rq); /* * take it off the sort and fifo list, move @@ -216,7 +222,7 @@ deadline_move_request(struct deadline_data *dd, struct request *rq) } /* - * deadline_check_fifo returns 0 if there are no expired reads on the fifo, + * deadline_check_fifo returns 0 if there are no expired requests on the fifo, * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir]) */ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) @@ -236,7 +242,7 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) * deadline_dispatch_requests selects the best request according to * read/write expire, fifo_batch, etc */ -static int deadline_dispatch_requests(request_queue_t *q, int force) +static int deadline_dispatch_requests(struct request_queue *q, int force) { struct deadline_data *dd = q->elevator->elevator_data; const int reads = !list_empty(&dd->fifo_list[READ]); @@ -252,17 +258,9 @@ static int deadline_dispatch_requests(request_queue_t *q, int force) else rq = dd->next_rq[READ]; - if (rq) { - /* we have a "next request" */ - - if (dd->last_sector != rq->sector) - /* end the batch on a non sequential request */ - dd->batching += dd->fifo_batch; - - if (dd->batching < dd->fifo_batch) - /* we are still entitled to batch */ - goto dispatch_request; - } + if (rq && dd->batching < dd->fifo_batch) + /* we have a next request are still entitled to batch */ + goto dispatch_request; /* * at this point we are not running a batch. select the appropriate @@ -301,30 +299,23 @@ dispatch_find_request: /* * we are not running a batch, find best request for selected data_dir */ - if (deadline_check_fifo(dd, data_dir)) { - /* An expired request exists - satisfy it */ - dd->batching = 0; + if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) { + /* + * A deadline has expired, the last request was in the other + * direction, or we have run out of higher-sectored requests. + * Start again from the request with the earliest expiry time. + */ rq = rq_entry_fifo(dd->fifo_list[data_dir].next); - - } else if (dd->next_rq[data_dir]) { + } else { /* * The last req was the same dir and we have a next request in * sort order. No expired requests so continue on from here. */ rq = dd->next_rq[data_dir]; - } else { - struct rb_node *node; - /* - * 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; - node = rb_first(&dd->sort_list[data_dir]); - if (node) - rq = rb_entry_rq(node); } + dd->batching = 0; + dispatch_request: /* * rq is the selected appropriate request. @@ -335,7 +326,7 @@ dispatch_request: return 1; } -static int deadline_queue_empty(request_queue_t *q) +static int deadline_queue_empty(struct request_queue *q) { struct deadline_data *dd = q->elevator->elevator_data; @@ -343,7 +334,7 @@ static int deadline_queue_empty(request_queue_t *q) && list_empty(&dd->fifo_list[READ]); } -static void deadline_exit_queue(elevator_t *e) +static void deadline_exit_queue(struct elevator_queue *e) { struct deadline_data *dd = e->elevator_data; @@ -356,14 +347,13 @@ static void deadline_exit_queue(elevator_t *e) /* * initialize elevator private data (deadline_data). */ -static void *deadline_init_queue(request_queue_t *q, elevator_t *e) +static void *deadline_init_queue(struct request_queue *q) { struct deadline_data *dd; - dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node); + dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node); if (!dd) return NULL; - memset(dd, 0, sizeof(*dd)); INIT_LIST_HEAD(&dd->fifo_list[READ]); INIT_LIST_HEAD(&dd->fifo_list[WRITE]); @@ -397,7 +387,7 @@ deadline_var_store(int *var, const char *page, size_t count) } #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ -static ssize_t __FUNC(elevator_t *e, char *page) \ +static ssize_t __FUNC(struct elevator_queue *e, char *page) \ { \ struct deadline_data *dd = e->elevator_data; \ int __data = __VAR; \ @@ -413,7 +403,7 @@ SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0); #undef SHOW_FUNCTION #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ -static ssize_t __FUNC(elevator_t *e, const char *page, size_t count) \ +static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ { \ struct deadline_data *dd = e->elevator_data; \ int __data; \ @@ -469,7 +459,9 @@ static struct elevator_type iosched_deadline = { static int __init deadline_init(void) { - return elv_register(&iosched_deadline); + elv_register(&iosched_deadline); + + return 0; } static void __exit deadline_exit(void)