}
EXPORT_SYMBOL(elv_rq_merge_ok);
-inline int elv_try_merge(struct request *__rq, struct bio *bio)
+static inline int elv_try_merge(struct request *__rq, struct bio *bio)
{
int ret = ELEVATOR_NO_MERGE;
return ret;
}
-EXPORT_SYMBOL(elv_try_merge);
static struct elevator_type *elevator_find(const char *name)
{
static char chosen_elevator[16];
-static void elevator_setup_default(void)
+static int __init elevator_setup(char *str)
{
- struct elevator_type *e;
-
/*
- * If default has not been set, use the compiled-in selection.
+ * Be backwards-compatible with previous kernels, so users
+ * won't get the wrong elevator.
*/
- if (!chosen_elevator[0])
- strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED);
-
- /*
- * If the given scheduler is not available, fall back to no-op.
- */
- if ((e = elevator_find(chosen_elevator)))
- elevator_put(e);
+ if (!strcmp(str, "as"))
+ strcpy(chosen_elevator, "anticipatory");
else
- strcpy(chosen_elevator, "noop");
-}
-
-static int __init elevator_setup(char *str)
-{
- strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
+ strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
return 0;
}
q->end_sector = 0;
q->boundary_rq = NULL;
- elevator_setup_default();
+ if (name && !(e = elevator_get(name)))
+ return -EINVAL;
- if (!name)
- name = chosen_elevator;
+ if (!e && *chosen_elevator && !(e = elevator_get(chosen_elevator)))
+ printk("I/O scheduler %s not found\n", chosen_elevator);
- e = elevator_get(name);
- if (!e)
- return -EINVAL;
+ if (!e && !(e = elevator_get(CONFIG_DEFAULT_IOSCHED))) {
+ printk("Default I/O scheduler not found, using no-op\n");
+ e = elevator_get("noop");
+ }
eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL);
if (!eq) {
rq->flags &= ~REQ_STARTED;
- /*
- * if this is the flush, requeue the original instead and drop the flush
- */
- if (rq->flags & REQ_BAR_FLUSH) {
- clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags);
- rq = rq->end_io_data;
- }
-
- __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+ elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE);
}
static void elv_drain_elevator(request_queue_t *q)
}
}
-void __elv_add_request(request_queue_t *q, struct request *rq, int where,
- int plug)
+void elv_insert(request_queue_t *q, struct request *rq, int where)
{
- if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
- /*
- * barriers implicitly indicate back insertion
- */
- if (where == ELEVATOR_INSERT_SORT)
- where = ELEVATOR_INSERT_BACK;
-
- /*
- * this request is scheduling boundary, update end_sector
- */
- if (blk_fs_request(rq)) {
- q->end_sector = rq_end_sector(rq);
- q->boundary_rq = rq;
- }
- } else if (!(rq->flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT)
- where = ELEVATOR_INSERT_BACK;
-
- if (plug)
- blk_plug_device(q);
+ struct list_head *pos;
+ unsigned ordseq;
rq->q = q;
q->elevator->ops->elevator_add_req_fn(q, rq);
break;
+ case ELEVATOR_INSERT_REQUEUE:
+ /*
+ * If ordered flush isn't in progress, we do front
+ * insertion; otherwise, requests should be requeued
+ * in ordseq order.
+ */
+ rq->flags |= REQ_SOFTBARRIER;
+
+ if (q->ordseq == 0) {
+ list_add(&rq->queuelist, &q->queue_head);
+ break;
+ }
+
+ ordseq = blk_ordered_req_seq(rq);
+
+ list_for_each(pos, &q->queue_head) {
+ struct request *pos_rq = list_entry_rq(pos);
+ if (ordseq <= blk_ordered_req_seq(pos_rq))
+ break;
+ }
+
+ list_add_tail(&rq->queuelist, pos);
+ break;
+
default:
printk(KERN_ERR "%s: bad insertion point %d\n",
__FUNCTION__, where);
}
}
+void __elv_add_request(request_queue_t *q, struct request *rq, int where,
+ int plug)
+{
+ if (q->ordcolor)
+ rq->flags |= REQ_ORDERED_COLOR;
+
+ if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
+ /*
+ * toggle ordered color
+ */
+ if (blk_barrier_rq(rq))
+ q->ordcolor ^= 1;
+
+ /*
+ * barriers implicitly indicate back insertion
+ */
+ if (where == ELEVATOR_INSERT_SORT)
+ where = ELEVATOR_INSERT_BACK;
+
+ /*
+ * this request is scheduling boundary, update
+ * end_sector
+ */
+ if (blk_fs_request(rq)) {
+ q->end_sector = rq_end_sector(rq);
+ q->boundary_rq = rq;
+ }
+ } else if (!(rq->flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT)
+ where = ELEVATOR_INSERT_BACK;
+
+ if (plug)
+ blk_plug_device(q);
+
+ elv_insert(q, rq, where);
+}
+
void elv_add_request(request_queue_t *q, struct request *rq, int where,
int plug)
{
{
struct request *rq;
- if (unlikely(list_empty(&q->queue_head) &&
- !q->elevator->ops->elevator_dispatch_fn(q, 0)))
- return NULL;
-
- rq = list_entry_rq(q->queue_head.next);
-
- /*
- * if this is a barrier write and the device has to issue a
- * flush sequence to support it, check how far we are
- */
- if (blk_fs_request(rq) && blk_barrier_rq(rq)) {
- BUG_ON(q->ordered == QUEUE_ORDERED_NONE);
+ while (1) {
+ while (!list_empty(&q->queue_head)) {
+ rq = list_entry_rq(q->queue_head.next);
+ if (blk_do_ordered(q, &rq))
+ return rq;
+ }
- if (q->ordered == QUEUE_ORDERED_FLUSH &&
- !blk_barrier_preflush(rq))
- rq = blk_start_pre_flush(q, rq);
+ if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
+ return NULL;
}
-
- return rq;
}
struct request *elv_next_request(request_queue_t *q)
blkdev_dequeue_request(rq);
rq->flags |= REQ_QUIET;
end_that_request_chunk(rq, 0, nr_bytes);
- end_that_request_last(rq);
+ end_that_request_last(rq, 0);
} else {
printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__,
ret);
if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
e->ops->elevator_completed_req_fn(q, rq);
}
+
+ /*
+ * Check if the queue is waiting for fs requests to be
+ * drained for flush sequence.
+ */
+ if (unlikely(q->ordseq)) {
+ struct request *first_rq = list_entry_rq(q->queue_head.next);
+ if (q->in_flight == 0 &&
+ blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
+ blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) {
+ blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
+ q->request_fn(q);
+ }
+ }
}
int elv_register_queue(struct request_queue *q)
spin_unlock_irq(&elv_list_lock);
printk(KERN_INFO "io scheduler %s registered", e->elevator_name);
- if (!strcmp(e->elevator_name, chosen_elevator))
- printk(" (default)");
+ if (!strcmp(e->elevator_name, chosen_elevator) ||
+ (!*chosen_elevator &&
+ !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
+ printk(" (default)");
printk("\n");
return 0;
}
projects / powerpc.git / blobdiff