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;
- __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE, 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)
{
struct list_head *pos;
unsigned ordseq;
- if (q->ordcolor)
- rq->flags |= REQ_ORDERED_COLOR;
-
- if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
- /*
- * toggle ordered color
- */
- 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);
-
rq->q = q;
switch (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)
{
* request is released from the driver, io must be done
*/
if (blk_account_rq(rq)) {
- struct request *first_rq = list_entry_rq(q->queue_head.next);
-
q->in_flight--;
+ 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 (q->ordseq && q->in_flight == 0 &&
+ /*
+ * 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);
}
-
- if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
- e->ops->elevator_completed_req_fn(q, rq);
}
}
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;
}