Patch from Nick Piggin <piggin@cyberone.com.au>
This adds helper functions to start and stop anticipation.
drivers/block/as-iosched.c | 96 +++++++++++++++++++++------------------------
1 files changed, 45 insertions(+), 51 deletions(-)
diff -puN drivers/block/as-iosched.c~as-start-stop-anticipation-helpers drivers/block/as-iosched.c
--- 25/drivers/block/as-iosched.c~as-start-stop-anticipation-helpers 2003-02-24 23:53:17.000000000 -0800
+++ 25-akpm/drivers/block/as-iosched.c 2003-02-24 23:53:17.000000000 -0800
@@ -623,9 +623,46 @@ static void as_anticipate_work(void *dat
spin_unlock_irqrestore(q->queue_lock, flags);
}
+static void as_start_anticipation(struct as_data *ad)
+{
+ struct request_queue *q = ad->q;
+ unsigned long timeout;
+
+ if (ad->antic_status == ANTIC_OFF) {
+ ant_stats.anticipate_starts++;
+ ad->antic_start = jiffies;
+ }
+ timeout = ad->antic_start + ad->antic_expire;
+#if 0
+ /* FIX THIS!!! */
+ timeout = min(timeout, ad->current_batch_expires);
+#endif
+ mod_timer(&ad->antic_timer, timeout);
+
+ ad->antic_status = ANTIC_WAIT;
+ blk_plug_device(q);
+}
+
+static void as_stop_anticipation_notimer(struct as_data *ad)
+{
+ if (ad->antic_status == ANTIC_WAIT) {
+ blk_remove_plug(ad->q);
+ schedule_work(&ad->antic_work);
+ }
+ ad->antic_status = ANTIC_FINISHED;
+}
+
+static void as_stop_anticipation(struct as_data *ad)
+{
+ if (ad->antic_status == ANTIC_WAIT)
+ del_timer(&ad->antic_timer);
+
+ as_stop_anticipation_notimer(ad);
+}
+
/*
* as_anticipate_timeout is the timer function set by
- * as_start_anticipate.
+ * as_start_anticipation.
*/
static void as_anticipate_timeout(unsigned long data)
{
@@ -634,13 +671,8 @@ static void as_anticipate_timeout(unsign
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
-
- ad->antic_status = ANTIC_FINISHED;
-
- blk_remove_plug(q);
- schedule_work(&ad->antic_work);
+ as_stop_anticipation_notimer(ad);
ant_stats.timeouts++;
-
spin_unlock_irqrestore(q->queue_lock, flags);
}
@@ -670,8 +702,7 @@ as_close_req(struct as_data *ad, struct
#define MAXBACK (512 * 1024)
static struct as_rq *
-as_choose_req(struct as_data *ad,
- struct as_rq *arq1, struct as_rq *arq2)
+as_choose_req(struct as_data *ad, struct as_rq *arq1, struct as_rq *arq2)
{
int data_dir;
sector_t last, s1, s2, d1, d2;
@@ -820,12 +851,7 @@ static void as_update_arq(struct as_data
ant_stats.lba_forward_offsets[log2]++;
}
- if (ad->antic_status == ANTIC_WAIT) {
- del_timer(&ad->antic_timer);
- blk_remove_plug(ad->q);
- schedule_work(&ad->antic_work);
- }
- ad->antic_status = ANTIC_FINISHED;
+ as_stop_anticipation(ad);
}
}
@@ -846,10 +872,7 @@ static int as_can_anticipate(struct as_d
* In this situation status should really be FINISHED, however
* the timer hasn't had the chance to run yet.
*/
- del_timer(&ad->antic_timer);
- ad->antic_status = ANTIC_FINISHED;
- blk_remove_plug(ad->q);
- schedule_work(&ad->antic_work);
+ as_stop_anticipation(ad);
return 0;
}
@@ -877,12 +900,9 @@ static int as_can_anticipate(struct as_d
*/
static int as_dispatch_request(struct as_data *ad)
{
- struct request_queue *q = ad->q;
struct as_rq *arq;
const int reads = !list_empty(&ad->fifo_list[READ]);
const int writes = !list_empty(&ad->fifo_list[WRITE]);
- static unsigned long last_read_id;
- static unsigned long last_finished;
if (!(reads || writes))
return 0;
@@ -905,22 +925,7 @@ static int as_dispatch_request(struct as
goto fifo_expired;
if (as_can_anticipate(ad, arq)) {
- unsigned long timeout;
-
- if (ad->antic_status == ANTIC_OFF) {
- ant_stats.anticipate_starts++;
- ad->antic_start = jiffies;
- }
- timeout = ad->antic_start + ad->antic_expire;
-#if 0
- /* FIX THIS!!! */
- timeout = min(timeout,
- ad->current_batch_expires);
-#endif
- mod_timer(&ad->antic_timer, timeout);
-
- ad->antic_status = ANTIC_WAIT;
- blk_plug_device(q);
+ as_start_anticipation(ad);
return 0;
}
@@ -997,13 +1002,6 @@ fifo_expired:
ad->antic_status = ANTIC_OFF;
as_move_request(ad, arq);
- if (ad->batch_data_dir == READ) {
- if (last_read_id != arq->request_id) {
- last_read_id = arq->request_id;
- }
- last_finished = arq->request->sector + arq->request->nr_sectors;
- }
-
return 1;
}
@@ -1039,12 +1037,8 @@ as_insert_request(request_queue_t *q, st
list_add(&rq->queuelist, insert_here);
if (!list_empty(ad->dispatch) && rq_data_dir(rq) == READ
- && ad->antic_status == ANTIC_WAIT) {
- del_timer(&ad->antic_timer);
- ad->antic_status = ANTIC_FINISHED;
- blk_remove_plug(q);
- schedule_work(&ad->antic_work);
- }
+ && ad->antic_status == ANTIC_WAIT)
+ as_stop_anticipation(ad);
return;
}
_