drbd: Load balancing method: striping (d60de03a) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/block/drbd/drbd_req.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -745,10 +745,11 @@ static bool drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int
		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 @@ static bool remote_due_to_read_balancing(struct drbd_conf *mdev)
		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 @@ int __drbd_make_request(struct drbd_conf mdev, struct bio bio, unsigned long s
		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;

+6 −0

Original line number	Diff line number	Diff line
		@@ -108,6 +108,12 @@ enum drbd_read_balancing {
		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. */