drbd: Load balancing method: striping
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 98251e2..5b28de0 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -745,10 +745,11 @@
return drbd_bm_count_bits(mdev, sbnr, ebnr) == 0;
}
-static bool remote_due_to_read_balancing(struct drbd_conf *mdev)
+static bool remote_due_to_read_balancing(struct drbd_conf *mdev, sector_t sector)
{
enum drbd_read_balancing rbm;
struct backing_dev_info *bdi;
+ int stripe_shift;
if (mdev->state.pdsk < D_UP_TO_DATE)
return false;
@@ -764,6 +765,14 @@
case RB_LEAST_PENDING:
return atomic_read(&mdev->local_cnt) >
atomic_read(&mdev->ap_pending_cnt) + atomic_read(&mdev->rs_pending_cnt);
+ case RB_32K_STRIPING: /* stripe_shift = 15 */
+ case RB_64K_STRIPING:
+ case RB_128K_STRIPING:
+ case RB_256K_STRIPING:
+ case RB_512K_STRIPING:
+ case RB_1M_STRIPING: /* stripe_shift = 20 */
+ stripe_shift = (rbm - RB_32K_STRIPING + 15);
+ return (sector >> (stripe_shift - 9)) & 1;
case RB_ROUND_ROBIN:
return test_and_change_bit(READ_BALANCE_RR, &mdev->flags);
case RB_PREFER_REMOTE:
@@ -841,7 +850,7 @@
bio_put(req->private_bio);
req->private_bio = NULL;
put_ldev(mdev);
- } else if (remote_due_to_read_balancing(mdev)) {
+ } else if (remote_due_to_read_balancing(mdev, sector)) {
/* Keep the private bio in case we need it
for a local retry */
local = 0;
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 157ba3d..1e86156 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -108,6 +108,12 @@
RB_ROUND_ROBIN,
RB_LEAST_PENDING,
RB_CONGESTED_REMOTE,
+ RB_32K_STRIPING,
+ RB_64K_STRIPING,
+ RB_128K_STRIPING,
+ RB_256K_STRIPING,
+ RB_512K_STRIPING,
+ RB_1M_STRIPING,
};
/* KEEP the order, do not delete or insert. Only append. */