diff options
author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-11-03 12:43:36 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-11-03 12:43:36 -0700 |
commit | b4f555081fdd27d13e6ff39d455d5aefae9d2c0c (patch) | |
tree | 917acaae9556ad2c372d001bf786cfbcf8102684 /block/deadline-iosched.c | |
parent | 160acc2e899f26356bde92bc257253b7ca78f0c3 (diff) | |
parent | 51fd77bd9f512ab6cc9df0733ba1caaab89eb957 (diff) |
Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
[BLOCK] Don't allow empty barriers to be passed down to queues that don't grok them
dm: bounce_pfn limit added
Deadline iosched: Fix batching fairness
Deadline iosched: Reset batch for ordered requests
Deadline iosched: Factor out finding latter reques
Diffstat (limited to 'block/deadline-iosched.c')
-rw-r--r-- | block/deadline-iosched.c | 53 |
1 files changed, 26 insertions, 27 deletions
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index 1a511ffaf8a..a054eef8dff 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c @@ -55,6 +55,20 @@ static void deadline_move_request(struct deadline_data *, struct request *); #define RQ_RB_ROOT(dd, rq) (&(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) { @@ -74,13 +88,8 @@ 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); - - dd->next_rq[data_dir] = NULL; - if (rbnext) - dd->next_rq[data_dir] = rb_entry_rq(rbnext); - } + if (dd->next_rq[data_dir] == rq) + dd->next_rq[data_dir] = deadline_latter_request(rq); elv_rb_del(RQ_RB_ROOT(dd, rq), rq); } @@ -198,14 +207,11 @@ 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; /* @@ -301,30 +307,23 @@ 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. |