cfq-iosched: get rid of ->cur_rr and ->cfq_list
It's only used for preemption now that the IDLE and RT queues also use the rbtree. If we pass an 'add_front' variable to cfq_service_tree_add(), we can set ->rb_key to 0 to force insertion at the front of the tree. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe
Jens Axboe
parent
67e6b49e39
commit
edd75ffd92
@ -45,9 +45,6 @@ static int cfq_slice_idle = HZ / 125;
|
||||
*/
|
||||
#define CFQ_QHASH_SHIFT 6
|
||||
#define CFQ_QHASH_ENTRIES (1 << CFQ_QHASH_SHIFT)
|
||||
#define list_entry_qhash(entry) hlist_entry((entry), struct cfq_queue, cfq_hash)
|
||||
|
||||
#define list_entry_cfqq(ptr) list_entry((ptr), struct cfq_queue, cfq_list)
|
||||
|
||||
#define RQ_CIC(rq) ((struct cfq_io_context*)(rq)->elevator_private)
|
||||
#define RQ_CFQQ(rq) ((rq)->elevator_private2)
|
||||
@ -91,7 +88,6 @@ struct cfq_data {
|
||||
* rr list of queues with requests and the count of them
|
||||
*/
|
||||
struct cfq_rb_root service_tree;
|
||||
struct list_head cur_rr;
|
||||
unsigned int busy_queues;
|
||||
|
||||
/*
|
||||
@ -146,8 +142,6 @@ struct cfq_queue {
|
||||
struct hlist_node cfq_hash;
|
||||
/* hash key */
|
||||
unsigned int key;
|
||||
/* member of the rr/busy/cur/idle cfqd list */
|
||||
struct list_head cfq_list;
|
||||
/* service_tree member */
|
||||
struct rb_node rb_node;
|
||||
/* service_tree key */
|
||||
@ -452,16 +446,19 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
|
||||
* we will service the queues.
|
||||
*/
|
||||
static void cfq_service_tree_add(struct cfq_data *cfqd,
|
||||
struct cfq_queue *cfqq)
|
||||
struct cfq_queue *cfqq, int add_front)
|
||||
{
|
||||
struct rb_node **p = &cfqd->service_tree.rb.rb_node;
|
||||
struct rb_node *parent = NULL;
|
||||
unsigned long rb_key;
|
||||
int left;
|
||||
|
||||
rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies;
|
||||
rb_key += cfqq->slice_resid;
|
||||
cfqq->slice_resid = 0;
|
||||
if (!add_front) {
|
||||
rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies;
|
||||
rb_key += cfqq->slice_resid;
|
||||
cfqq->slice_resid = 0;
|
||||
} else
|
||||
rb_key = 0;
|
||||
|
||||
if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
|
||||
/*
|
||||
@ -516,13 +513,13 @@ static void cfq_service_tree_add(struct cfq_data *cfqd,
|
||||
/*
|
||||
* Update cfqq's position in the service tree.
|
||||
*/
|
||||
static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
|
||||
static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq)
|
||||
{
|
||||
/*
|
||||
* Resorting requires the cfqq to be on the RR list already.
|
||||
*/
|
||||
if (cfq_cfqq_on_rr(cfqq))
|
||||
cfq_service_tree_add(cfqq->cfqd, cfqq);
|
||||
cfq_service_tree_add(cfqd, cfqq, 0);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -536,7 +533,7 @@ cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
|
||||
cfq_mark_cfqq_on_rr(cfqq);
|
||||
cfqd->busy_queues++;
|
||||
|
||||
cfq_resort_rr_list(cfqq, 0);
|
||||
cfq_resort_rr_list(cfqd, cfqq);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -548,7 +545,6 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
|
||||
{
|
||||
BUG_ON(!cfq_cfqq_on_rr(cfqq));
|
||||
cfq_clear_cfqq_on_rr(cfqq);
|
||||
list_del_init(&cfqq->cfq_list);
|
||||
|
||||
if (!RB_EMPTY_NODE(&cfqq->rb_node))
|
||||
cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree);
|
||||
@ -771,7 +767,7 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
|
||||
if (timed_out && !cfq_cfqq_slice_new(cfqq))
|
||||
cfqq->slice_resid = cfqq->slice_end - jiffies;
|
||||
|
||||
cfq_resort_rr_list(cfqq, preempted);
|
||||
cfq_resort_rr_list(cfqd, cfqq);
|
||||
|
||||
if (cfqq == cfqd->active_queue)
|
||||
cfqd->active_queue = NULL;
|
||||
@ -799,31 +795,28 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, int preempted,
|
||||
*/
|
||||
static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
|
||||
{
|
||||
struct cfq_queue *cfqq = NULL;
|
||||
struct cfq_queue *cfqq;
|
||||
struct rb_node *n;
|
||||
|
||||
if (RB_EMPTY_ROOT(&cfqd->service_tree.rb))
|
||||
return NULL;
|
||||
|
||||
n = cfq_rb_first(&cfqd->service_tree);
|
||||
cfqq = rb_entry(n, struct cfq_queue, rb_node);
|
||||
|
||||
if (cfq_class_idle(cfqq)) {
|
||||
unsigned long end;
|
||||
|
||||
if (!list_empty(&cfqd->cur_rr)) {
|
||||
/*
|
||||
* if current list is non-empty, grab first entry.
|
||||
* if we have idle queues and no rt or be queues had
|
||||
* pending requests, either allow immediate service if
|
||||
* the grace period has passed or arm the idle grace
|
||||
* timer
|
||||
*/
|
||||
cfqq = list_entry_cfqq(cfqd->cur_rr.next);
|
||||
} else if (!RB_EMPTY_ROOT(&cfqd->service_tree.rb)) {
|
||||
struct rb_node *n = cfq_rb_first(&cfqd->service_tree);
|
||||
|
||||
cfqq = rb_entry(n, struct cfq_queue, rb_node);
|
||||
if (cfq_class_idle(cfqq)) {
|
||||
unsigned long end;
|
||||
|
||||
/*
|
||||
* if we have idle queues and no rt or be queues had
|
||||
* pending requests, either allow immediate service if
|
||||
* the grace period has passed or arm the idle grace
|
||||
* timer
|
||||
*/
|
||||
end = cfqd->last_end_request + CFQ_IDLE_GRACE;
|
||||
if (time_before(jiffies, end)) {
|
||||
mod_timer(&cfqd->idle_class_timer, end);
|
||||
cfqq = NULL;
|
||||
}
|
||||
end = cfqd->last_end_request + CFQ_IDLE_GRACE;
|
||||
if (time_before(jiffies, end)) {
|
||||
mod_timer(&cfqd->idle_class_timer, end);
|
||||
cfqq = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
@ -1075,18 +1068,6 @@ static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
|
||||
return dispatched;
|
||||
}
|
||||
|
||||
static int cfq_forced_dispatch_cfqqs(struct list_head *list)
|
||||
{
|
||||
struct cfq_queue *cfqq, *next;
|
||||
int dispatched;
|
||||
|
||||
dispatched = 0;
|
||||
list_for_each_entry_safe(cfqq, next, list, cfq_list)
|
||||
dispatched += __cfq_forced_dispatch_cfqq(cfqq);
|
||||
|
||||
return dispatched;
|
||||
}
|
||||
|
||||
/*
|
||||
* Drain our current requests. Used for barriers and when switching
|
||||
* io schedulers on-the-fly.
|
||||
@ -1102,8 +1083,6 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd)
|
||||
dispatched += __cfq_forced_dispatch_cfqq(cfqq);
|
||||
}
|
||||
|
||||
dispatched += cfq_forced_dispatch_cfqqs(&cfqd->cur_rr);
|
||||
|
||||
cfq_slice_expired(cfqd, 0, 0);
|
||||
|
||||
BUG_ON(cfqd->busy_queues);
|
||||
@ -1433,7 +1412,6 @@ retry:
|
||||
memset(cfqq, 0, sizeof(*cfqq));
|
||||
|
||||
INIT_HLIST_NODE(&cfqq->cfq_hash);
|
||||
INIT_LIST_HEAD(&cfqq->cfq_list);
|
||||
RB_CLEAR_NODE(&cfqq->rb_node);
|
||||
INIT_LIST_HEAD(&cfqq->fifo);
|
||||
|
||||
@ -1712,8 +1690,8 @@ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
|
||||
* so we know that it will be selected next.
|
||||
*/
|
||||
BUG_ON(!cfq_cfqq_on_rr(cfqq));
|
||||
list_del_init(&cfqq->cfq_list);
|
||||
list_add(&cfqq->cfq_list, &cfqd->cur_rr);
|
||||
|
||||
cfq_service_tree_add(cfqd, cfqq, 1);
|
||||
|
||||
cfqq->slice_end = 0;
|
||||
cfq_mark_cfqq_slice_new(cfqq);
|
||||
@ -2077,7 +2055,6 @@ static void *cfq_init_queue(request_queue_t *q)
|
||||
memset(cfqd, 0, sizeof(*cfqd));
|
||||
|
||||
cfqd->service_tree = CFQ_RB_ROOT;
|
||||
INIT_LIST_HEAD(&cfqd->cur_rr);
|
||||
INIT_LIST_HEAD(&cfqd->cic_list);
|
||||
|
||||
cfqd->cfq_hash = kmalloc_node(sizeof(struct hlist_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL, q->node);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user