[BLOCK] Unify the seperate read/write io stat fields into arrays
Instead of having ->read_sectors and ->write_sectors, combine the two
into ->sectors[2] and similar for the other fields. This saves a branch
several places in the io path, since we don't have to care for what the
actual io direction is. On my x86-64 box, that's 200 bytes less text in
just the core (not counting the various drivers).
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 2a8a569..9ecf51e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3466,8 +3466,8 @@
idle = 1;
ITERATE_RDEV(mddev,rdev,tmp) {
struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
- curr_events = disk_stat_read(disk, read_sectors) +
- disk_stat_read(disk, write_sectors) -
+ curr_events = disk_stat_read(disk, sectors[0]) +
+ disk_stat_read(disk, sectors[1]) -
atomic_read(&disk->sync_io);
/* Allow some slack between valud of curr_events and last_events,
* as there are some uninteresting races.