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| author | Tatyana Brokhman <tlinder@codeaurora.org> | 2012-12-04 16:04:15 +0200 |
|---|---|---|
| committer | Pawit Pornkitprasan <p.pawit@gmail.com> | 2013-02-09 14:17:26 +0700 |
| commit | 80468a9a39033524ea8df3394690f76e72de51f0 (patch) | |
| tree | cfd9782f7c25201ce095158e72cfed538d67ceb9 /include | |
| parent | ab8ebd66d16b2e79d13ba756d63461e52a0300bc (diff) | |
| download | kernel_samsung_aries-80468a9a39033524ea8df3394690f76e72de51f0.zip kernel_samsung_aries-80468a9a39033524ea8df3394690f76e72de51f0.tar.gz kernel_samsung_aries-80468a9a39033524ea8df3394690f76e72de51f0.tar.bz2 | |
block: Add API for urgent request handling
This patch add support in block & elevator layers for handling
urgent requests. The decision if a request is urgent or not is taken
by the scheduler. Urgent request notification is passed to the underlying
block device driver (eMMC for example). Block device driver may decide to
interrupt the currently running low priority request to serve the new
urgent request. By doing so READ latency is greatly reduced in read&write
collision scenarios.
Note that if the current scheduler doesn't implement the urgent request
mechanism, this code path is never activated.
Change-Id: I8aa74b9b45c0d3a2221bd4e82ea76eb4103e7cfa
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blkdev.h | 4 | ||||
| -rw-r--r-- | include/linux/elevator.h | 2 |
2 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 305dc58..981ba53 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -275,6 +275,7 @@ struct request_queue struct request_list rq; request_fn_proc *request_fn; + request_fn_proc *urgent_request_fn; make_request_fn *make_request_fn; prep_rq_fn *prep_rq_fn; unprep_rq_fn *unprep_rq_fn; @@ -350,6 +351,8 @@ struct request_queue struct list_head timeout_list; struct queue_limits limits; + bool notified_urgent; + bool dispatched_urgent; /* * sg stuff @@ -806,6 +809,7 @@ extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn, extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *); extern struct request_queue *blk_init_allocated_queue(struct request_queue *, request_fn_proc *, spinlock_t *); +extern void blk_urgent_request(struct request_queue *q, request_fn_proc *fn); extern void blk_cleanup_queue(struct request_queue *); extern void blk_queue_make_request(struct request_queue *, make_request_fn *); extern void blk_queue_bounce_limit(struct request_queue *, u64); diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 00ff62d..e5b50ba 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -22,6 +22,7 @@ typedef int (elevator_dispatch_fn) (struct request_queue *, int); typedef void (elevator_add_req_fn) (struct request_queue *, struct request *); typedef int (elevator_reinsert_req_fn) (struct request_queue *, struct request *); +typedef bool (elevator_is_urgent_fn) (struct request_queue *); typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *); typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *); typedef int (elevator_may_queue_fn) (struct request_queue *, int); @@ -45,6 +46,7 @@ struct elevator_ops elevator_dispatch_fn *elevator_dispatch_fn; elevator_add_req_fn *elevator_add_req_fn; elevator_reinsert_req_fn *elevator_reinsert_req_fn; + elevator_is_urgent_fn *elevator_is_urgent_fn; elevator_activate_req_fn *elevator_activate_req_fn; elevator_deactivate_req_fn *elevator_deactivate_req_fn; |