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block: remove elevator_queue->ops
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elevator_queue->ops points to the same ops struct ->elevator_type.ops
is pointing to.  The only effect of caching it in elevator_queue is
shorter notation - it doesn't save any indirect derefence.

Relocate elevator_type->list which used only during module init/exit
to the end of the structure, rename elevator_queue->elevator_type to
->type, and replace elevator_queue->ops with elevator_queue->type.ops.

This doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Tejun Heo authored and Jens Axboe committed Dec 13, 2011
1 parent f8fc877 commit 22f746e
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Showing 3 changed files with 43 additions and 46 deletions.
10 changes: 5 additions & 5 deletions block/blk.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -94,7 +94,7 @@ static inline struct request *__elv_next_request(struct request_queue *q)
return NULL;
}
if (unlikely(blk_queue_dead(q)) ||
!q->elevator->ops->elevator_dispatch_fn(q, 0))
!q->elevator->type->ops.elevator_dispatch_fn(q, 0))
return NULL;
}
}
Expand All @@ -103,16 +103,16 @@ static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_activate_req_fn)
e->ops->elevator_activate_req_fn(q, rq);
if (e->type->ops.elevator_activate_req_fn)
e->type->ops.elevator_activate_req_fn(q, rq);
}

static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_deactivate_req_fn)
e->ops->elevator_deactivate_req_fn(q, rq);
if (e->type->ops.elevator_deactivate_req_fn)
e->type->ops.elevator_deactivate_req_fn(q, rq);
}

#ifdef CONFIG_FAIL_IO_TIMEOUT
Expand Down
74 changes: 36 additions & 38 deletions block/elevator.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,8 +61,8 @@ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
struct request_queue *q = rq->q;
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_allow_merge_fn)
return e->ops->elevator_allow_merge_fn(q, rq, bio);
if (e->type->ops.elevator_allow_merge_fn)
return e->type->ops.elevator_allow_merge_fn(q, rq, bio);

return 1;
}
Expand Down Expand Up @@ -171,7 +171,7 @@ static struct elevator_type *elevator_get(const char *name)
static int elevator_init_queue(struct request_queue *q,
struct elevator_queue *eq)
{
eq->elevator_data = eq->ops->elevator_init_fn(q);
eq->elevator_data = eq->type->ops.elevator_init_fn(q);
if (eq->elevator_data)
return 0;
return -ENOMEM;
Expand Down Expand Up @@ -203,8 +203,7 @@ static struct elevator_queue *elevator_alloc(struct request_queue *q,
if (unlikely(!eq))
goto err;

eq->ops = &e->ops;
eq->elevator_type = e;
eq->type = e;
kobject_init(&eq->kobj, &elv_ktype);
mutex_init(&eq->sysfs_lock);

Expand All @@ -228,7 +227,7 @@ static void elevator_release(struct kobject *kobj)
struct elevator_queue *e;

e = container_of(kobj, struct elevator_queue, kobj);
elevator_put(e->elevator_type);
elevator_put(e->type);
kfree(e->hash);
kfree(e);
}
Expand Down Expand Up @@ -288,9 +287,8 @@ EXPORT_SYMBOL(elevator_init);
void elevator_exit(struct elevator_queue *e)
{
mutex_lock(&e->sysfs_lock);
if (e->ops->elevator_exit_fn)
e->ops->elevator_exit_fn(e);
e->ops = NULL;
if (e->type->ops.elevator_exit_fn)
e->type->ops.elevator_exit_fn(e);
mutex_unlock(&e->sysfs_lock);

kobject_put(&e->kobj);
Expand Down Expand Up @@ -500,8 +498,8 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
return ELEVATOR_BACK_MERGE;
}

if (e->ops->elevator_merge_fn)
return e->ops->elevator_merge_fn(q, req, bio);
if (e->type->ops.elevator_merge_fn)
return e->type->ops.elevator_merge_fn(q, req, bio);

return ELEVATOR_NO_MERGE;
}
Expand Down Expand Up @@ -544,8 +542,8 @@ void elv_merged_request(struct request_queue *q, struct request *rq, int type)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_merged_fn)
e->ops->elevator_merged_fn(q, rq, type);
if (e->type->ops.elevator_merged_fn)
e->type->ops.elevator_merged_fn(q, rq, type);

if (type == ELEVATOR_BACK_MERGE)
elv_rqhash_reposition(q, rq);
Expand All @@ -559,8 +557,8 @@ void elv_merge_requests(struct request_queue *q, struct request *rq,
struct elevator_queue *e = q->elevator;
const int next_sorted = next->cmd_flags & REQ_SORTED;

if (next_sorted && e->ops->elevator_merge_req_fn)
e->ops->elevator_merge_req_fn(q, rq, next);
if (next_sorted && e->type->ops.elevator_merge_req_fn)
e->type->ops.elevator_merge_req_fn(q, rq, next);

elv_rqhash_reposition(q, rq);

Expand All @@ -577,8 +575,8 @@ void elv_bio_merged(struct request_queue *q, struct request *rq,
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_bio_merged_fn)
e->ops->elevator_bio_merged_fn(q, rq, bio);
if (e->type->ops.elevator_bio_merged_fn)
e->type->ops.elevator_bio_merged_fn(q, rq, bio);
}

void elv_requeue_request(struct request_queue *q, struct request *rq)
Expand All @@ -604,12 +602,12 @@ void elv_drain_elevator(struct request_queue *q)

lockdep_assert_held(q->queue_lock);

while (q->elevator->ops->elevator_dispatch_fn(q, 1))
while (q->elevator->type->ops.elevator_dispatch_fn(q, 1))
;
if (q->nr_sorted && printed++ < 10) {
printk(KERN_ERR "%s: forced dispatching is broken "
"(nr_sorted=%u), please report this\n",
q->elevator->elevator_type->elevator_name, q->nr_sorted);
q->elevator->type->elevator_name, q->nr_sorted);
}
}

Expand Down Expand Up @@ -698,7 +696,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
* rq cannot be accessed after calling
* elevator_add_req_fn.
*/
q->elevator->ops->elevator_add_req_fn(q, rq);
q->elevator->type->ops.elevator_add_req_fn(q, rq);
break;

case ELEVATOR_INSERT_FLUSH:
Expand Down Expand Up @@ -727,26 +725,26 @@ struct request *elv_latter_request(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_latter_req_fn)
return e->ops->elevator_latter_req_fn(q, rq);
if (e->type->ops.elevator_latter_req_fn)
return e->type->ops.elevator_latter_req_fn(q, rq);
return NULL;
}

struct request *elv_former_request(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_former_req_fn)
return e->ops->elevator_former_req_fn(q, rq);
if (e->type->ops.elevator_former_req_fn)
return e->type->ops.elevator_former_req_fn(q, rq);
return NULL;
}

int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_set_req_fn)
return e->ops->elevator_set_req_fn(q, rq, gfp_mask);
if (e->type->ops.elevator_set_req_fn)
return e->type->ops.elevator_set_req_fn(q, rq, gfp_mask);

rq->elevator_private[0] = NULL;
return 0;
Expand All @@ -756,16 +754,16 @@ void elv_put_request(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_put_req_fn)
e->ops->elevator_put_req_fn(rq);
if (e->type->ops.elevator_put_req_fn)
e->type->ops.elevator_put_req_fn(rq);
}

int elv_may_queue(struct request_queue *q, int rw)
{
struct elevator_queue *e = q->elevator;

if (e->ops->elevator_may_queue_fn)
return e->ops->elevator_may_queue_fn(q, rw);
if (e->type->ops.elevator_may_queue_fn)
return e->type->ops.elevator_may_queue_fn(q, rw);

return ELV_MQUEUE_MAY;
}
Expand Down Expand Up @@ -800,8 +798,8 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
if (blk_account_rq(rq)) {
q->in_flight[rq_is_sync(rq)]--;
if ((rq->cmd_flags & REQ_SORTED) &&
e->ops->elevator_completed_req_fn)
e->ops->elevator_completed_req_fn(q, rq);
e->type->ops.elevator_completed_req_fn)
e->type->ops.elevator_completed_req_fn(q, rq);
}
}

Expand All @@ -819,7 +817,7 @@ elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page)

e = container_of(kobj, struct elevator_queue, kobj);
mutex_lock(&e->sysfs_lock);
error = e->ops ? entry->show(e, page) : -ENOENT;
error = e->type ? entry->show(e, page) : -ENOENT;
mutex_unlock(&e->sysfs_lock);
return error;
}
Expand All @@ -837,7 +835,7 @@ elv_attr_store(struct kobject *kobj, struct attribute *attr,

e = container_of(kobj, struct elevator_queue, kobj);
mutex_lock(&e->sysfs_lock);
error = e->ops ? entry->store(e, page, length) : -ENOENT;
error = e->type ? entry->store(e, page, length) : -ENOENT;
mutex_unlock(&e->sysfs_lock);
return error;
}
Expand All @@ -858,7 +856,7 @@ int __elv_register_queue(struct request_queue *q, struct elevator_queue *e)

error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched");
if (!error) {
struct elv_fs_entry *attr = e->elevator_type->elevator_attrs;
struct elv_fs_entry *attr = e->type->elevator_attrs;
if (attr) {
while (attr->attr.name) {
if (sysfs_create_file(&e->kobj, &attr->attr))
Expand Down Expand Up @@ -959,7 +957,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
elevator_exit(old_elevator);
elv_quiesce_end(q);

blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name);
blk_add_trace_msg(q, "elv switch: %s", e->type->elevator_name);

return 0;

Expand Down Expand Up @@ -993,7 +991,7 @@ int elevator_change(struct request_queue *q, const char *name)
return -EINVAL;
}

if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name)) {
if (!strcmp(elevator_name, q->elevator->type->elevator_name)) {
elevator_put(e);
return 0;
}
Expand Down Expand Up @@ -1028,7 +1026,7 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name)
if (!q->elevator || !blk_queue_stackable(q))
return sprintf(name, "none\n");

elv = e->elevator_type;
elv = e->type;

spin_lock(&elv_list_lock);
list_for_each_entry(__e, &elv_list, list) {
Expand Down
5 changes: 2 additions & 3 deletions include/linux/elevator.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -78,22 +78,21 @@ struct elv_fs_entry {
*/
struct elevator_type
{
struct list_head list;
struct elevator_ops ops;
struct elv_fs_entry *elevator_attrs;
char elevator_name[ELV_NAME_MAX];
struct module *elevator_owner;
struct list_head list;
};

/*
* each queue has an elevator_queue associated with it
*/
struct elevator_queue
{
struct elevator_ops *ops;
struct elevator_type *type;
void *elevator_data;
struct kobject kobj;
struct elevator_type *elevator_type;
struct mutex sysfs_lock;
struct hlist_head *hash;
unsigned int registered:1;
Expand Down

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