Commit 6f757231 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Jens Axboe

dm: remove the pending IO accounting

Remove the "pending" atomic counters, that duplicate block-core's
in_flight counters, and update md_in_flight() to look at percpu
in_flight counters.
Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e016b782
...@@ -65,7 +65,6 @@ struct mapped_device { ...@@ -65,7 +65,6 @@ struct mapped_device {
*/ */
struct work_struct work; struct work_struct work;
wait_queue_head_t wait; wait_queue_head_t wait;
atomic_t pending[2];
spinlock_t deferred_lock; spinlock_t deferred_lock;
struct bio_list deferred; struct bio_list deferred;
...@@ -119,7 +118,6 @@ struct mapped_device { ...@@ -119,7 +118,6 @@ struct mapped_device {
struct srcu_struct io_barrier; struct srcu_struct io_barrier;
}; };
int md_in_flight(struct mapped_device *md);
void disable_write_same(struct mapped_device *md); void disable_write_same(struct mapped_device *md);
void disable_write_zeroes(struct mapped_device *md); void disable_write_zeroes(struct mapped_device *md);
......
...@@ -646,25 +646,30 @@ static void free_tio(struct dm_target_io *tio) ...@@ -646,25 +646,30 @@ static void free_tio(struct dm_target_io *tio)
bio_put(&tio->clone); bio_put(&tio->clone);
} }
int md_in_flight(struct mapped_device *md) static bool md_in_flight(struct mapped_device *md)
{ {
return atomic_read(&md->pending[READ]) + int cpu;
atomic_read(&md->pending[WRITE]); struct hd_struct *part = &dm_disk(md)->part0;
for_each_possible_cpu(cpu) {
if (part_stat_local_read_cpu(part, in_flight[0], cpu) ||
part_stat_local_read_cpu(part, in_flight[1], cpu))
return true;
}
return false;
} }
static void start_io_acct(struct dm_io *io) static void start_io_acct(struct dm_io *io)
{ {
struct mapped_device *md = io->md; struct mapped_device *md = io->md;
struct bio *bio = io->orig_bio; struct bio *bio = io->orig_bio;
int rw = bio_data_dir(bio);
io->start_time = jiffies; io->start_time = jiffies;
generic_start_io_acct(md->queue, bio_op(bio), bio_sectors(bio), generic_start_io_acct(md->queue, bio_op(bio), bio_sectors(bio),
&dm_disk(md)->part0); &dm_disk(md)->part0);
atomic_inc(&md->pending[rw]);
if (unlikely(dm_stats_used(&md->stats))) if (unlikely(dm_stats_used(&md->stats)))
dm_stats_account_io(&md->stats, bio_data_dir(bio), dm_stats_account_io(&md->stats, bio_data_dir(bio),
bio->bi_iter.bi_sector, bio_sectors(bio), bio->bi_iter.bi_sector, bio_sectors(bio),
...@@ -676,8 +681,6 @@ static void end_io_acct(struct dm_io *io) ...@@ -676,8 +681,6 @@ static void end_io_acct(struct dm_io *io)
struct mapped_device *md = io->md; struct mapped_device *md = io->md;
struct bio *bio = io->orig_bio; struct bio *bio = io->orig_bio;
unsigned long duration = jiffies - io->start_time; unsigned long duration = jiffies - io->start_time;
int pending;
int rw = bio_data_dir(bio);
generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0, generic_end_io_acct(md->queue, bio_op(bio), &dm_disk(md)->part0,
io->start_time); io->start_time);
...@@ -687,16 +690,11 @@ static void end_io_acct(struct dm_io *io) ...@@ -687,16 +690,11 @@ static void end_io_acct(struct dm_io *io)
bio->bi_iter.bi_sector, bio_sectors(bio), bio->bi_iter.bi_sector, bio_sectors(bio),
true, duration, &io->stats_aux); 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 */ /* nudge anyone waiting on suspend queue */
if (!pending) if (unlikely(waitqueue_active(&md->wait))) {
if (!md_in_flight(md))
wake_up(&md->wait); wake_up(&md->wait);
}
} }
/* /*
...@@ -1915,8 +1913,6 @@ static struct mapped_device *alloc_dev(int minor) ...@@ -1915,8 +1913,6 @@ static struct mapped_device *alloc_dev(int minor)
if (!md->disk) if (!md->disk)
goto bad; goto bad;
atomic_set(&md->pending[0], 0);
atomic_set(&md->pending[1], 0);
init_waitqueue_head(&md->wait); init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work); INIT_WORK(&md->work, dm_wq_work);
init_waitqueue_head(&md->eventq); init_waitqueue_head(&md->eventq);
......
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