diff options
author | Mike Snitzer <snitzer@redhat.com> | 2011-02-11 11:08:00 +0100 |
---|---|---|
committer | Jens Axboe <jaxboe@fusionio.com> | 2011-02-11 11:08:00 +0100 |
commit | c186794dbb466b45cf40f942f2d09d6d5b4b0e42 (patch) | |
tree | 07ccd819bb6cced2c19053d2ed97ebaac88f824e | |
parent | 9d5a4e946ce5352f19400b6370f4cd8e72806278 (diff) | |
download | kernel_samsung_crespo-c186794dbb466b45cf40f942f2d09d6d5b4b0e42.zip kernel_samsung_crespo-c186794dbb466b45cf40f942f2d09d6d5b4b0e42.tar.gz kernel_samsung_crespo-c186794dbb466b45cf40f942f2d09d6d5b4b0e42.tar.bz2 |
block: share request flush fields with elevator_private
Flush requests are never put on the IO scheduler. Convert request
structure's elevator_private* into an array and have the flush fields
share a union with it.
Reclaim the space lost in 'struct request' by moving 'completion_data'
back in the union with 'rb_node'.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
-rw-r--r-- | block/cfq-iosched.c | 18 | ||||
-rw-r--r-- | block/elevator.c | 2 | ||||
-rw-r--r-- | include/linux/blkdev.h | 23 |
3 files changed, 22 insertions, 21 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 4cd59b0..968455c 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -54,9 +54,9 @@ static const int cfq_hist_divisor = 4; #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8) #define RQ_CIC(rq) \ - ((struct cfq_io_context *) (rq)->elevator_private) -#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) -#define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elevator_private3) + ((struct cfq_io_context *) (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]) static struct kmem_cache *cfq_pool; static struct kmem_cache *cfq_ioc_pool; @@ -3589,12 +3589,12 @@ static void cfq_put_request(struct request *rq) put_io_context(RQ_CIC(rq)->ioc); - rq->elevator_private = NULL; - rq->elevator_private2 = NULL; + rq->elevator_private[0] = NULL; + rq->elevator_private[1] = NULL; /* Put down rq reference on cfqg */ cfq_put_cfqg(RQ_CFQG(rq)); - rq->elevator_private3 = NULL; + rq->elevator_private[2] = NULL; cfq_put_queue(cfqq); } @@ -3685,9 +3685,9 @@ new_queue: spin_unlock_irqrestore(q->queue_lock, flags); - rq->elevator_private = cic; - rq->elevator_private2 = cfqq; - rq->elevator_private3 = cfq_ref_get_cfqg(cfqq->cfqg); + rq->elevator_private[0] = cic; + rq->elevator_private[1] = cfqq; + rq->elevator_private[2] = cfq_ref_get_cfqg(cfqq->cfqg); return 0; queue_fail: diff --git a/block/elevator.c b/block/elevator.c index 270e097..f98e92e 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -764,7 +764,7 @@ int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) if (e->ops->elevator_set_req_fn) return e->ops->elevator_set_req_fn(q, rq, gfp_mask); - rq->elevator_private = NULL; + rq->elevator_private[0] = NULL; return 0; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6d7e9af..12bb426 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -99,25 +99,26 @@ struct request { /* * The rb_node is only used inside the io scheduler, requests * are pruned when moved to the dispatch queue. So let the - * flush fields share space with the rb_node. + * completion_data share space with the rb_node. */ union { struct rb_node rb_node; /* sort/lookup */ - struct { - unsigned int seq; - struct list_head list; - } flush; + void *completion_data; }; - void *completion_data; - /* * Three pointers are available for the IO schedulers, if they need - * more they have to dynamically allocate it. + * 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. */ - void *elevator_private; - void *elevator_private2; - void *elevator_private3; + union { + void *elevator_private[3]; + struct { + unsigned int seq; + struct list_head list; + } flush; + }; struct gendisk *rq_disk; unsigned long start_time; |