*
* Copyright (C) 2003 Jens Axboe <axboe@suse.de>
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/elevator.h>
static const int cfq_slice_sync = HZ / 10;
static int cfq_slice_async = HZ / 25;
static const int cfq_slice_async_rq = 2;
-static int cfq_slice_idle = HZ / 70;
+static int cfq_slice_idle = HZ / 125;
#define CFQ_IDLE_GRACE (HZ / 10)
#define CFQ_SLICE_SCALE (5)
/*
* rb-tree defines
*/
-#define RB_EMPTY(node) ((node)->rb_node == NULL)
-#define RB_CLEAR(node) do { \
- memset(node, 0, sizeof(*node)); \
-} while (0)
-#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL)
#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node)
#define rq_rb_key(rq) (rq)->sector
rb_erase(&crq->rb_node, &cfqq->sort_list);
- if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
+ if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
cfq_del_cfqq_rr(cfqd, cfqq);
}
return cfqq;
}
+#define CIC_SEEKY(cic) ((cic)->seek_mean > (128 * 1024))
+
static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
struct cfq_io_context *cic;
unsigned long sl;
- WARN_ON(!RB_EMPTY(&cfqq->sort_list));
+ WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
WARN_ON(cfqq != cfqd->active_queue);
/*
* fair distribution of slice time for a process doing back-to-back
* seeks. so allow a little bit of time for him to submit a new rq
*/
- if (sample_valid(cic->seek_samples) && cic->seek_mean > 131072)
- sl = 2;
+ if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic))
+ sl = min(sl, msecs_to_jiffies(2));
mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
return 1;
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_queue *cfqq = crq->cfq_queue;
+ struct request *rq;
cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);
cfq_remove_request(crq->request);
cfqq->on_dispatch[cfq_crq_is_sync(crq)]++;
elv_dispatch_sort(q, crq->request);
+
+ rq = list_entry(q->queue_head.prev, struct request, queuelist);
+ cfqd->last_sector = rq->sector + rq->nr_sectors;
}
/*
* if queue has requests, dispatch one. if not, check if
* enough slice is left to wait for one
*/
- if (!RB_EMPTY(&cfqq->sort_list))
+ if (!RB_EMPTY_ROOT(&cfqq->sort_list))
goto keep_queue;
- else if (cfq_cfqq_class_sync(cfqq) &&
- time_before(now, cfqq->slice_end)) {
+ else if (cfq_cfqq_dispatched(cfqq)) {
+ cfqq = NULL;
+ goto keep_queue;
+ } else if (cfq_cfqq_class_sync(cfqq)) {
if (cfq_arm_slice_timer(cfqd, cfqq))
return NULL;
}
{
int dispatched = 0;
- BUG_ON(RB_EMPTY(&cfqq->sort_list));
+ BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
do {
struct cfq_rq *crq;
cfqd->active_cic = crq->io_context;
}
- if (RB_EMPTY(&cfqq->sort_list))
+ if (RB_EMPTY_ROOT(&cfqq->sort_list))
break;
} while (dispatched < max_dispatch);
/*
- * if slice end isn't set yet, set it. if at least one request was
- * sync, use the sync time slice value
+ * if slice end isn't set yet, set it.
*/
if (!cfqq->slice_end)
cfq_set_prio_slice(cfqd, cfqq);
*/
if ((!cfq_cfqq_sync(cfqq) &&
cfqd->dispatch_slice >= cfq_prio_to_maxrq(cfqd, cfqq)) ||
- cfq_class_idle(cfqq))
+ cfq_class_idle(cfqq) ||
+ !cfq_cfqq_idle_window(cfqq))
cfq_slice_expired(cfqd, 0);
return dispatched;
static int
cfq_forced_dispatch_cfqqs(struct list_head *list)
{
- int dispatched = 0;
struct cfq_queue *cfqq, *next;
struct cfq_rq *crq;
+ int dispatched;
+ dispatched = 0;
list_for_each_entry_safe(cfqq, next, list, cfq_list) {
while ((crq = cfqq->next_crq)) {
cfq_dispatch_insert(cfqq->cfqd->queue, crq);
}
BUG_ON(!list_empty(&cfqq->fifo));
}
+
return dispatched;
}
cfq_dispatch_requests(request_queue_t *q, int force)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
- struct cfq_queue *cfqq;
+ struct cfq_queue *cfqq, *prev_cfqq;
+ int dispatched;
if (!cfqd->busy_queues)
return 0;
if (unlikely(force))
return cfq_forced_dispatch(cfqd);
- cfqq = cfq_select_queue(cfqd);
- if (cfqq) {
+ dispatched = 0;
+ prev_cfqq = NULL;
+ while ((cfqq = cfq_select_queue(cfqd)) != NULL) {
int max_dispatch;
+ /*
+ * Don't repeat dispatch from the previous queue.
+ */
+ if (prev_cfqq == cfqq)
+ break;
+
cfq_clear_cfqq_must_dispatch(cfqq);
cfq_clear_cfqq_wait_request(cfqq);
del_timer(&cfqd->idle_slice_timer);
if (cfq_class_idle(cfqq))
max_dispatch = 1;
- return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
+ dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
+
+ /*
+ * If the dispatch cfqq has idling enabled and is still
+ * the active queue, break out.
+ */
+ if (cfq_cfqq_idle_window(cfqq) && cfqd->active_queue)
+ break;
+
+ prev_cfqq = cfqq;
}
- return 0;
+ return dispatched;
}
/*
{
struct cfq_data *cfqd = cic->key;
struct cfq_queue *cfqq;
- if (cfqd) {
- spin_lock(cfqd->queue->queue_lock);
- cfqq = cic->cfqq[ASYNC];
- if (cfqq) {
- struct cfq_queue *new_cfqq;
- new_cfqq = cfq_get_queue(cfqd, CFQ_KEY_ASYNC,
- cic->ioc->task, GFP_ATOMIC);
- if (new_cfqq) {
- cic->cfqq[ASYNC] = new_cfqq;
- cfq_put_queue(cfqq);
- }
- }
- cfqq = cic->cfqq[SYNC];
- if (cfqq) {
- cfq_mark_cfqq_prio_changed(cfqq);
- cfq_init_prio_data(cfqq);
+
+ if (unlikely(!cfqd))
+ return;
+
+ spin_lock(cfqd->queue->queue_lock);
+
+ cfqq = cic->cfqq[ASYNC];
+ if (cfqq) {
+ struct cfq_queue *new_cfqq;
+ new_cfqq = cfq_get_queue(cfqd, CFQ_KEY_ASYNC, cic->ioc->task,
+ GFP_ATOMIC);
+ if (new_cfqq) {
+ cic->cfqq[ASYNC] = new_cfqq;
+ cfq_put_queue(cfqq);
}
- spin_unlock(cfqd->queue->queue_lock);
}
+
+ cfqq = cic->cfqq[SYNC];
+ if (cfqq)
+ cfq_mark_cfqq_prio_changed(cfqq);
+
+ spin_unlock(cfqd->queue->queue_lock);
}
/*
INIT_HLIST_NODE(&cfqq->cfq_hash);
INIT_LIST_HEAD(&cfqq->cfq_list);
- RB_CLEAR_ROOT(&cfqq->sort_list);
INIT_LIST_HEAD(&cfqq->fifo);
cfqq->key = key;
* set ->slice_left to allow preemption for a new process
*/
cfqq->slice_left = 2 * cfqd->cfq_slice_idle;
- if (!cfqd->hw_tag)
- cfq_mark_cfqq_idle_window(cfqq);
+ cfq_mark_cfqq_idle_window(cfqq);
cfq_mark_cfqq_prio_changed(cfqq);
cfq_init_prio_data(cfqq);
}
/* ->key must be copied to avoid race with cfq_exit_queue() */
k = __cic->key;
if (unlikely(!k)) {
- cfq_drop_dead_cic(ioc, cic);
+ cfq_drop_dead_cic(ioc, __cic);
goto restart;
}
{
int enable_idle = cfq_cfqq_idle_window(cfqq);
- if (!cic->ioc->task || !cfqd->cfq_slice_idle || cfqd->hw_tag)
+ if (!cic->ioc->task || !cfqd->cfq_slice_idle ||
+ (cfqd->hw_tag && CIC_SEEKY(cic)))
enable_idle = 0;
else if (sample_valid(cic->ttime_samples)) {
if (cic->ttime_mean > cfqd->cfq_slice_idle)
return 0;
if (!cfqq)
- return 1;
+ return 0;
if (cfq_class_idle(cfqq))
return 1;
cfqq->slice_left = cfq_prio_to_slice(cfqd, cfqq) / 2;
cfqq->slice_end = cfqq->slice_left + jiffies;
- __cfq_slice_expired(cfqd, cfqq, 1);
+ cfq_slice_expired(cfqd, 1);
__cfq_set_active_queue(cfqd, cfqq);
}
cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct cfq_rq *crq)
{
- struct cfq_io_context *cic;
-
- cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq);
-
- cic = crq->io_context;
+ struct cfq_io_context *cic = crq->io_context;
/*
* we never wait for an async request and we don't allow preemption
cfqq->service_last = now;
cfq_resort_rr_list(cfqq, 0);
}
- cfq_schedule_dispatch(cfqd);
}
- if (cfq_crq_is_sync(crq))
+ if (sync)
crq->io_context->last_end_request = now;
+
+ /*
+ * If this is the active queue, check if it needs to be expired,
+ * or if we want to idle in case it has no pending requests.
+ */
+ if (cfqd->active_queue == cfqq) {
+ if (time_after(now, cfqq->slice_end))
+ cfq_slice_expired(cfqd, 0);
+ else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list)) {
+ if (!cfq_arm_slice_timer(cfqd, cfqq))
+ cfq_schedule_dispatch(cfqd);
+ }
+ }
}
static struct request *
crq = mempool_alloc(cfqd->crq_pool, gfp_mask);
if (crq) {
- RB_CLEAR(&crq->rb_node);
+ RB_CLEAR_NODE(&crq->rb_node);
crq->rb_key = 0;
crq->request = rq;
INIT_HLIST_NODE(&crq->hash);
* only expire and reinvoke request handler, if there are
* other queues with pending requests
*/
- if (!cfqd->busy_queues) {
- cfqd->idle_slice_timer.expires = min(now + cfqd->cfq_slice_idle, cfqq->slice_end);
- add_timer(&cfqd->idle_slice_timer);
+ if (!cfqd->busy_queues)
goto out_cont;
- }
/*
* not expired and it has a request pending, let it dispatch
*/
- if (!RB_EMPTY(&cfqq->sort_list)) {
+ if (!RB_EMPTY_ROOT(&cfqq->sort_list)) {
cfq_mark_cfqq_must_dispatch(cfqq);
goto out_kick;
}
git.openpandora.org / pandora-kernel.git / blobdiff