Remove the "pending" variable and use dm_disk(md)->part0.in_flight.
These variables hold identical values.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-core.h | 1 -
drivers/md/dm-rq.c | 4 ++--
drivers/md/dm.c | 34 ++++++++++++++++------------------
3 files changed, 18 insertions(+), 21 deletions(-)
Index: linux-2.6/drivers/md/dm-core.h
===================================================================
--- linux-2.6.orig/drivers/md/dm-core.h 2018-10-25 00:47:12.000000000 +0200
+++ linux-2.6/drivers/md/dm-core.h 2018-10-25 00:47:12.000000000 +0200
@@ -65,7 +65,6 @@ struct mapped_device {
*/
struct work_struct work;
wait_queue_head_t wait;
- atomic_t pending[2];
spinlock_t deferred_lock;
struct bio_list deferred;
Index: linux-2.6/drivers/md/dm.c
===================================================================
--- linux-2.6.orig/drivers/md/dm.c 2018-10-25 00:47:12.000000000 +0200
+++ linux-2.6/drivers/md/dm.c 2018-10-25 00:47:28.000000000 +0200
@@ -597,23 +597,20 @@ static void free_tio(struct dm_target_io
int md_in_flight(struct mapped_device *md)
{
- return atomic_read(&md->pending[READ]) +
- atomic_read(&md->pending[WRITE]);
+ return atomic_read(&dm_disk(md)->part0.in_flight[READ]) +
+ atomic_read(&dm_disk(md)->part0.in_flight[WRITE]);
}
static void start_io_acct(struct dm_io *io)
{
struct mapped_device *md = io->md;
struct bio *bio = io->orig_bio;
- int rw = bio_data_dir(bio);
io->start_time = jiffies;
generic_start_io_acct(md->queue, bio_op(bio), bio_sectors(bio),
&dm_disk(md)->part0);
- atomic_inc(&md->pending[rw]);
-
if (unlikely(dm_stats_used(&md->stats)))
dm_stats_account_io(&md->stats, bio_data_dir(bio),
bio->bi_iter.bi_sector, bio_sectors(bio),
@@ -625,27 +622,30 @@ static void end_io_acct(struct dm_io *io
struct mapped_device *md = io->md;
struct bio *bio = io->orig_bio;
unsigned long duration = jiffies - io->start_time;
- int pending;
- int rw = bio_data_dir(bio);
+ /*
+ * make sure that atomic_dec in generic_end_io_acct is not reordered
+ * with previous writes
+ */
+ smp_mb__before_atomic();
generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0,
io->start_time);
+ /*
+ * generic_end_io_acct does atomic_dec, this barrier makes sure that
+ * atomic_dec is not reordered with waitqueue_active
+ */
+ smp_mb__after_atomic();
if (unlikely(dm_stats_used(&md->stats)))
dm_stats_account_io(&md->stats, bio_data_dir(bio),
bio->bi_iter.bi_sector, bio_sectors(bio),
true, duration, &io->stats_aux);
- /*
- * After this is decremented the bio must not be touched if it is
- * a flush.
- */
- pending = atomic_dec_return(&md->pending[rw]);
- pending += atomic_read(&md->pending[rw^0x1]);
-
/* nudge anyone waiting on suspend queue */
- if (!pending)
- wake_up(&md->wait);
+ if (unlikely(waitqueue_active(&md->wait))) {
+ if (!md_in_flight(md))
+ wake_up(&md->wait);
+ }
}
/*
@@ -1899,8 +1899,6 @@ static struct mapped_device *alloc_dev(i
if (!md->disk)
goto bad;
- atomic_set(&md->pending[0], 0);
- atomic_set(&md->pending[1], 0);
init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work);
init_waitqueue_head(&md->eventq);
Index: linux-2.6/drivers/md/dm-rq.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-rq.c 2018-10-25 00:47:12.000000000 +0200
+++ linux-2.6/drivers/md/dm-rq.c 2018-10-25 00:47:12.000000000 +0200
@@ -182,7 +182,7 @@ static void rq_completed(struct mapped_d
struct request_queue *q = md->queue;
unsigned long flags;
- atomic_dec(&md->pending[rw]);
+ atomic_dec(&dm_disk(md)->part0.in_flight[rw]);
/* nudge anyone waiting on suspend queue */
if (!md_in_flight(md))
@@ -536,7 +536,7 @@ static void dm_start_request(struct mapp
blk_start_request(orig);
else
blk_mq_start_request(orig);
- atomic_inc(&md->pending[rq_data_dir(orig)]);
+ atomic_inc(&dm_disk(md)->part0.in_flight[rq_data_dir(orig)]);
if (md->seq_rq_merge_deadline_usecs) {
md->last_rq_pos = rq_end_sector(orig);
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
