Patch from: Hugh Dickins <hugh@veritas.com>
Removes a ton of dead code from ll_rw_blk.c. I'm not completely sure that
the dead code won't be needed, so keep this patch in -mm for a while.
drivers/block/ll_rw_blk.c | 65 +++++++-------------------------------------
include/linux/backing-dev.h | 12 --------
2 files changed, 11 insertions(+), 66 deletions(-)
diff -puN drivers/block/ll_rw_blk.c~remove-unused-congestion-stuff drivers/block/ll_rw_blk.c
--- 25/drivers/block/ll_rw_blk.c~remove-unused-congestion-stuff 2003-03-14 20:28:34.000000000 -0800
+++ 25-akpm/drivers/block/ll_rw_blk.c 2003-03-14 20:28:34.000000000 -0800
@@ -56,11 +56,7 @@ static int batch_requests;
unsigned long blk_max_low_pfn, blk_max_pfn;
int blk_nohighio = 0;
-static struct congestion_state {
- wait_queue_head_t wqh;
- atomic_t nr_congested_queues;
- atomic_t nr_active_queues;
-} congestion_states[2];
+static wait_queue_head_t congestion_wqh[2];
/*
* Return the threshold (number of free requests) at which the queue is
@@ -98,14 +94,12 @@ static inline int queue_congestion_off_t
static void clear_queue_congested(request_queue_t *q, int rw)
{
enum bdi_state bit;
- struct congestion_state *cs = &congestion_states[rw];
+ wait_queue_head_t *wqh = &congestion_wqh[rw];
bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested;
-
- if (test_and_clear_bit(bit, &q->backing_dev_info.state))
- atomic_dec(&cs->nr_congested_queues);
- if (waitqueue_active(&cs->wqh))
- wake_up(&cs->wqh);
+ clear_bit(bit, &q->backing_dev_info.state);
+ if (waitqueue_active(wqh))
+ wake_up(wqh);
}
/*
@@ -117,37 +111,7 @@ static void set_queue_congested(request_
enum bdi_state bit;
bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested;
-
- if (!test_and_set_bit(bit, &q->backing_dev_info.state))
- atomic_inc(&congestion_states[rw].nr_congested_queues);
-}
-
-/*
- * A queue has just put back its last read or write request and has fallen
- * idle.
- */
-static void clear_queue_active(request_queue_t *q, int rw)
-{
- enum bdi_state bit;
-
- bit = (rw == WRITE) ? BDI_write_active : BDI_read_active;
-
- if (test_and_clear_bit(bit, &q->backing_dev_info.state))
- atomic_dec(&congestion_states[rw].nr_active_queues);
-}
-
-/*
- * A queue has just taken its first read or write request and has become
- * active.
- */
-static void set_queue_active(request_queue_t *q, int rw)
-{
- enum bdi_state bit;
-
- bit = (rw == WRITE) ? BDI_write_active : BDI_read_active;
-
- if (!test_and_set_bit(bit, &q->backing_dev_info.state))
- atomic_inc(&congestion_states[rw].nr_active_queues);
+ set_bit(bit, &q->backing_dev_info.state);
}
/**
@@ -1325,8 +1289,6 @@ static struct request *get_request(reque
rq = blkdev_free_rq(&rl->free);
list_del_init(&rq->queuelist);
rq->ref_count = 1;
- if (rl->count == queue_nr_requests)
- set_queue_active(q, rw);
rl->count--;
if (rl->count < queue_congestion_on_threshold())
set_queue_congested(q, rw);
@@ -1569,8 +1531,6 @@ void __blk_put_request(request_queue_t *
rl->count++;
if (rl->count >= queue_congestion_off_threshold())
clear_queue_congested(q, rw);
- if (rl->count == queue_nr_requests)
- clear_queue_active(q, rw);
if (rl->count >= batch_requests && waitqueue_active(&rl->wait))
wake_up(&rl->wait);
}
@@ -1605,12 +1565,12 @@ void blk_put_request(struct request *req
void blk_congestion_wait(int rw, long timeout)
{
DEFINE_WAIT(wait);
- struct congestion_state *cs = &congestion_states[rw];
+ wait_queue_head_t *wqh = &congestion_wqh[rw];
blk_run_queues();
- prepare_to_wait(&cs->wqh, &wait, TASK_UNINTERRUPTIBLE);
+ prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
io_schedule_timeout(timeout);
- finish_wait(&cs->wqh, &wait);
+ finish_wait(wqh, &wait);
}
/*
@@ -2249,11 +2209,8 @@ int __init blk_dev_init(void)
blk_max_low_pfn = max_low_pfn;
blk_max_pfn = max_pfn;
- for (i = 0; i < ARRAY_SIZE(congestion_states); i++) {
- init_waitqueue_head(&congestion_states[i].wqh);
- atomic_set(&congestion_states[i].nr_congested_queues, 0);
- atomic_set(&congestion_states[i].nr_active_queues, 0);
- }
+ for (i = 0; i < ARRAY_SIZE(congestion_wqh); i++)
+ init_waitqueue_head(&congestion_wqh[i]);
return 0;
};
diff -puN include/linux/backing-dev.h~remove-unused-congestion-stuff include/linux/backing-dev.h
--- 25/include/linux/backing-dev.h~remove-unused-congestion-stuff 2003-03-14 20:28:34.000000000 -0800
+++ 25-akpm/include/linux/backing-dev.h 2003-03-14 20:28:34.000000000 -0800
@@ -17,8 +17,6 @@ enum bdi_state {
BDI_pdflush, /* A pdflush thread is working this device */
BDI_write_congested, /* The write queue is getting full */
BDI_read_congested, /* The read queue is getting full */
- BDI_write_active, /* There are one or more queued writes */
- BDI_read_active, /* There are one or more queued reads */
BDI_unused, /* Available bits start here */
};
@@ -44,14 +42,4 @@ static inline int bdi_write_congested(st
return test_bit(BDI_write_congested, &bdi->state);
}
-static inline int bdi_read_active(struct backing_dev_info *bdi)
-{
- return test_bit(BDI_read_active, &bdi->state);
-}
-
-static inline int bdi_write_active(struct backing_dev_info *bdi)
-{
- return test_bit(BDI_write_active, &bdi->state);
-}
-
#endif /* _LINUX_BACKING_DEV_H */
_