diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 485ed8c..352441b 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -550,12 +550,6 @@
 	u32	offset;	 /* usecs the probe got sent after the reference time point */
 } __packed;
 
-struct delay_probe {
-	struct list_head list;
-	unsigned int seq_num;
-	struct timeval time;
-};
-
 /* DCBP: Drbd Compressed Bitmap Packet ... */
 static inline enum drbd_bitmap_code
 DCBP_get_code(struct p_compressed_bm *p)
@@ -942,11 +936,9 @@
 	unsigned int ko_count;
 	struct drbd_work  resync_work,
 			  unplug_work,
-			  md_sync_work,
-			  delay_probe_work;
+			  md_sync_work;
 	struct timer_list resync_timer;
 	struct timer_list md_sync_timer;
-	struct timer_list delay_probe_timer;
 
 	/* Used after attach while negotiating new disk state. */
 	union drbd_state new_state_tmp;
@@ -1062,12 +1054,6 @@
 	u64 ed_uuid; /* UUID of the exposed data */
 	struct mutex state_mutex;
 	char congestion_reason;  /* Why we where congested... */
-	struct list_head delay_probes; /* protected by peer_seq_lock */
-	int data_delay;   /* Delay of packets on the data-sock behind meta-sock */
-	unsigned int delay_seq; /* To generate sequence numbers of delay probes */
-	struct timeval dps_time; /* delay-probes-start-time */
-	unsigned int dp_volume_last;  /* send_cnt of last delay probe */
-	int c_sync_rate; /* current resync rate after delay_probe magic */
 };
 
 static inline struct drbd_conf *minor_to_mdev(unsigned int minor)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 668f063..fa650dd 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2184,43 +2184,6 @@
 	return ok;
 }
 
-static int drbd_send_delay_probe(struct drbd_conf *mdev, struct drbd_socket *ds)
-{
-	struct p_delay_probe dp;
-	int offset, ok = 0;
-	struct timeval now;
-
-	mutex_lock(&ds->mutex);
-	if (likely(ds->socket)) {
-		do_gettimeofday(&now);
-		offset = now.tv_usec - mdev->dps_time.tv_usec +
-			 (now.tv_sec - mdev->dps_time.tv_sec) * 1000000;
-		dp.seq_num  = cpu_to_be32(mdev->delay_seq);
-		dp.offset   = cpu_to_be32(offset);
-
-		ok = _drbd_send_cmd(mdev, ds->socket, P_DELAY_PROBE,
-				    (struct p_header *)&dp, sizeof(dp), 0);
-	}
-	mutex_unlock(&ds->mutex);
-
-	return ok;
-}
-
-static int drbd_send_delay_probes(struct drbd_conf *mdev)
-{
-	int ok;
-
-	mdev->delay_seq++;
-	do_gettimeofday(&mdev->dps_time);
-	ok = drbd_send_delay_probe(mdev, &mdev->meta);
-	ok = ok && drbd_send_delay_probe(mdev, &mdev->data);
-
-	mdev->dp_volume_last = mdev->send_cnt;
-	mod_timer(&mdev->delay_probe_timer, jiffies + mdev->sync_conf.dp_interval * HZ / 10);
-
-	return ok;
-}
-
 /* called on sndtimeo
  * returns FALSE if we should retry,
  * TRUE if we think connection is dead
@@ -2369,27 +2332,6 @@
 	return 1;
 }
 
-static void consider_delay_probes(struct drbd_conf *mdev)
-{
-	return;
-}
-
-static int w_delay_probes(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
-{
-	if (!cancel && mdev->state.conn == C_SYNC_SOURCE)
-		drbd_send_delay_probes(mdev);
-
-	return 1;
-}
-
-static void delay_probe_timer_fn(unsigned long data)
-{
-	struct drbd_conf *mdev = (struct drbd_conf *) data;
-
-	if (list_empty(&mdev->delay_probe_work.list))
-		drbd_queue_work(&mdev->data.work, &mdev->delay_probe_work);
-}
-
 /* Used to send write requests
  * R_PRIMARY -> Peer	(P_DATA)
  */
@@ -2453,9 +2395,6 @@
 
 	drbd_put_data_sock(mdev);
 
-	if (ok)
-		consider_delay_probes(mdev);
-
 	return ok;
 }
 
@@ -2502,9 +2441,6 @@
 
 	drbd_put_data_sock(mdev);
 
-	if (ok)
-		consider_delay_probes(mdev);
-
 	return ok;
 }
 
@@ -2666,10 +2602,6 @@
 		/* .rate = */		DRBD_RATE_DEF,
 		/* .after = */		DRBD_AFTER_DEF,
 		/* .al_extents = */	DRBD_AL_EXTENTS_DEF,
-		/* .dp_volume = */	DRBD_DP_VOLUME_DEF,
-		/* .dp_interval = */	DRBD_DP_INTERVAL_DEF,
-		/* .throttle_th = */	DRBD_RS_THROTTLE_TH_DEF,
-		/* .hold_off_th = */	DRBD_RS_HOLD_OFF_TH_DEF,
 		/* .verify_alg = */	{}, 0,
 		/* .cpu_mask = */	{}, 0,
 		/* .csums_alg = */	{}, 0,
@@ -2736,24 +2668,17 @@
 	INIT_LIST_HEAD(&mdev->unplug_work.list);
 	INIT_LIST_HEAD(&mdev->md_sync_work.list);
 	INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
-	INIT_LIST_HEAD(&mdev->delay_probes);
-	INIT_LIST_HEAD(&mdev->delay_probe_work.list);
 
 	mdev->resync_work.cb  = w_resync_inactive;
 	mdev->unplug_work.cb  = w_send_write_hint;
 	mdev->md_sync_work.cb = w_md_sync;
 	mdev->bm_io_work.w.cb = w_bitmap_io;
-	mdev->delay_probe_work.cb = w_delay_probes;
 	init_timer(&mdev->resync_timer);
 	init_timer(&mdev->md_sync_timer);
-	init_timer(&mdev->delay_probe_timer);
 	mdev->resync_timer.function = resync_timer_fn;
 	mdev->resync_timer.data = (unsigned long) mdev;
 	mdev->md_sync_timer.function = md_sync_timer_fn;
 	mdev->md_sync_timer.data = (unsigned long) mdev;
-	mdev->delay_probe_timer.function = delay_probe_timer_fn;
-	mdev->delay_probe_timer.data = (unsigned long) mdev;
-
 
 	init_waitqueue_head(&mdev->misc_wait);
 	init_waitqueue_head(&mdev->state_wait);
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 2151f18..73131c5 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1557,10 +1557,6 @@
 		sc.rate       = DRBD_RATE_DEF;
 		sc.after      = DRBD_AFTER_DEF;
 		sc.al_extents = DRBD_AL_EXTENTS_DEF;
-		sc.dp_volume  = DRBD_DP_VOLUME_DEF;
-		sc.dp_interval = DRBD_DP_INTERVAL_DEF;
-		sc.throttle_th = DRBD_RS_THROTTLE_TH_DEF;
-		sc.hold_off_th = DRBD_RS_HOLD_OFF_TH_DEF;
 	} else
 		memcpy(&sc, &mdev->sync_conf, sizeof(struct syncer_conf));
 
diff --git a/drivers/block/drbd/drbd_proc.c b/drivers/block/drbd/drbd_proc.c
index d0f1767..be3374b 100644
--- a/drivers/block/drbd/drbd_proc.c
+++ b/drivers/block/drbd/drbd_proc.c
@@ -73,21 +73,14 @@
 	seq_printf(seq, "sync'ed:%3u.%u%% ", res / 10, res % 10);
 	/* if more than 1 GB display in MB */
 	if (mdev->rs_total > 0x100000L)
-		seq_printf(seq, "(%lu/%lu)M",
+		seq_printf(seq, "(%lu/%lu)M\n\t",
 			    (unsigned long) Bit2KB(rs_left >> 10),
 			    (unsigned long) Bit2KB(mdev->rs_total >> 10));
 	else
-		seq_printf(seq, "(%lu/%lu)K",
+		seq_printf(seq, "(%lu/%lu)K\n\t",
 			    (unsigned long) Bit2KB(rs_left),
 			    (unsigned long) Bit2KB(mdev->rs_total));
 
-	if (mdev->state.conn == C_SYNC_TARGET)
-		seq_printf(seq, " queue_delay: %d.%d ms\n\t",
-			   mdev->data_delay / 1000,
-			   (mdev->data_delay % 1000) / 100);
-	else if (mdev->state.conn == C_SYNC_SOURCE)
-		seq_printf(seq, " delay_probe: %u\n\t", mdev->delay_seq);
-
 	/* see drivers/md/md.c
 	 * We do not want to overflow, so the order of operands and
 	 * the * 100 / 100 trick are important. We do a +1 to be
@@ -135,14 +128,6 @@
 	else
 		seq_printf(seq, " (%ld)", dbdt);
 
-	if (mdev->state.conn == C_SYNC_TARGET) {
-		if (mdev->c_sync_rate > 1000)
-			seq_printf(seq, " want: %d,%03d",
-				   mdev->c_sync_rate / 1000, mdev->c_sync_rate % 1000);
-		else
-			seq_printf(seq, " want: %d", mdev->c_sync_rate);
-	}
-
 	seq_printf(seq, " K/sec\n");
 }
 
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index cba1deb..20abef5 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3555,14 +3555,15 @@
 	return ok;
 }
 
-static int receive_skip(struct drbd_conf *mdev, struct p_header *h)
+static int receive_skip_(struct drbd_conf *mdev, struct p_header *h, int silent)
 {
 	/* TODO zero copy sink :) */
 	static char sink[128];
 	int size, want, r;
 
-	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
-	     h->command, h->length);
+	if (!silent)
+		dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
+		     h->command, h->length);
 
 	size = h->length;
 	while (size > 0) {
@@ -3574,6 +3575,16 @@
 	return size == 0;
 }
 
+static int receive_skip(struct drbd_conf *mdev, struct p_header *h)
+{
+	return receive_skip_(mdev, h, 0);
+}
+
+static int receive_skip_silent(struct drbd_conf *mdev, struct p_header *h)
+{
+	return receive_skip_(mdev, h, 1);
+}
+
 static int receive_UnplugRemote(struct drbd_conf *mdev, struct p_header *h)
 {
 	if (mdev->state.disk >= D_INCONSISTENT)
@@ -3586,92 +3597,6 @@
 	return TRUE;
 }
 
-static void timeval_sub_us(struct timeval* tv, unsigned int us)
-{
-	tv->tv_sec -= us / 1000000;
-	us = us % 1000000;
-	if (tv->tv_usec > us) {
-		tv->tv_usec += 1000000;
-		tv->tv_sec--;
-	}
-	tv->tv_usec -= us;
-}
-
-static void got_delay_probe(struct drbd_conf *mdev, int from, struct p_delay_probe *p)
-{
-	struct delay_probe *dp;
-	struct list_head *le;
-	struct timeval now;
-	int seq_num;
-	int offset;
-	int data_delay;
-
-	seq_num = be32_to_cpu(p->seq_num);
-	offset  = be32_to_cpu(p->offset);
-
-	spin_lock(&mdev->peer_seq_lock);
-	if (!list_empty(&mdev->delay_probes)) {
-		if (from == USE_DATA_SOCKET)
-			le = mdev->delay_probes.next;
-		else
-			le = mdev->delay_probes.prev;
-
-		dp = list_entry(le, struct delay_probe, list);
-
-		if (dp->seq_num == seq_num) {
-			list_del(le);
-			spin_unlock(&mdev->peer_seq_lock);
-			do_gettimeofday(&now);
-			timeval_sub_us(&now, offset);
-			data_delay =
-				now.tv_usec - dp->time.tv_usec +
-				(now.tv_sec - dp->time.tv_sec) * 1000000;
-
-			if (data_delay > 0)
-				mdev->data_delay = data_delay;
-
-			kfree(dp);
-			return;
-		}
-
-		if (dp->seq_num > seq_num) {
-			spin_unlock(&mdev->peer_seq_lock);
-			dev_warn(DEV, "Previous allocation failure of struct delay_probe?\n");
-			return; /* Do not alloca a struct delay_probe.... */
-		}
-	}
-	spin_unlock(&mdev->peer_seq_lock);
-
-	dp = kmalloc(sizeof(struct delay_probe), GFP_NOIO);
-	if (!dp) {
-		dev_warn(DEV, "Failed to allocate a struct delay_probe, do not worry.\n");
-		return;
-	}
-
-	dp->seq_num = seq_num;
-	do_gettimeofday(&dp->time);
-	timeval_sub_us(&dp->time, offset);
-
-	spin_lock(&mdev->peer_seq_lock);
-	if (from == USE_DATA_SOCKET)
-		list_add(&dp->list, &mdev->delay_probes);
-	else
-		list_add_tail(&dp->list, &mdev->delay_probes);
-	spin_unlock(&mdev->peer_seq_lock);
-}
-
-static int receive_delay_probe(struct drbd_conf *mdev, struct p_header *h)
-{
-	struct p_delay_probe *p = (struct p_delay_probe *)h;
-
-	ERR_IF(h->length != (sizeof(*p)-sizeof(*h))) return FALSE;
-	if (drbd_recv(mdev, h->payload, h->length) != h->length)
-		return FALSE;
-
-	got_delay_probe(mdev, USE_DATA_SOCKET, p);
-	return TRUE;
-}
-
 typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, struct p_header *);
 
 static drbd_cmd_handler_f drbd_default_handler[] = {
@@ -3695,7 +3620,7 @@
 	[P_OV_REQUEST]      = receive_DataRequest,
 	[P_OV_REPLY]        = receive_DataRequest,
 	[P_CSUM_RS_REQUEST]    = receive_DataRequest,
-	[P_DELAY_PROBE]     = receive_delay_probe,
+	[P_DELAY_PROBE]     = receive_skip_silent,
 	/* anything missing from this table is in
 	 * the asender_tbl, see get_asender_cmd */
 	[P_MAX_CMD]	    = NULL,
@@ -4472,11 +4397,9 @@
 	return TRUE;
 }
 
-static int got_delay_probe_m(struct drbd_conf *mdev, struct p_header *h)
+static int got_something_to_ignore_m(struct drbd_conf *mdev, struct p_header *h)
 {
-	struct p_delay_probe *p = (struct p_delay_probe *)h;
-
-	got_delay_probe(mdev, USE_META_SOCKET, p);
+	/* IGNORE */
 	return TRUE;
 }
 
@@ -4504,7 +4427,7 @@
 	[P_BARRIER_ACK]	    = { sizeof(struct p_barrier_ack), got_BarrierAck },
 	[P_STATE_CHG_REPLY] = { sizeof(struct p_req_state_reply), got_RqSReply },
 	[P_RS_IS_IN_SYNC]   = { sizeof(struct p_block_ack), got_IsInSync },
-	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe), got_delay_probe_m },
+	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe), got_something_to_ignore_m },
 	[P_MAX_CMD]	    = { 0, NULL },
 	};
 	if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL)
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index b623cee..ca4a16c 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -424,18 +424,6 @@
 		drbd_queue_work(&mdev->data.work, &mdev->resync_work);
 }
 
-static int calc_resync_rate(struct drbd_conf *mdev)
-{
-	int d = mdev->data_delay / 1000; /* us -> ms */
-	int td = mdev->sync_conf.throttle_th * 100;  /* 0.1s -> ms */
-	int hd = mdev->sync_conf.hold_off_th * 100;  /* 0.1s -> ms */
-	int cr = mdev->sync_conf.rate;
-
-	return d <= td ? cr :
-		d >= hd ? 0 :
-		cr + (cr * (td - d) / (hd - td));
-}
-
 int w_make_resync_request(struct drbd_conf *mdev,
 		struct drbd_work *w, int cancel)
 {
@@ -473,8 +461,7 @@
 	max_segment_size = mdev->agreed_pro_version < 94 ?
 		queue_max_segment_size(mdev->rq_queue) : DRBD_MAX_SEGMENT_SIZE;
 
-	mdev->c_sync_rate = calc_resync_rate(mdev);
-	number = SLEEP_TIME * mdev->c_sync_rate  / ((BM_BLOCK_SIZE / 1024) * HZ);
+	number = SLEEP_TIME * mdev->sync_conf.rate  / ((BM_BLOCK_SIZE / 1024) * HZ);
 	pe = atomic_read(&mdev->rs_pending_cnt);
 
 	mutex_lock(&mdev->data.mutex);
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index b8d2516..479ee3a 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -53,7 +53,7 @@
 
 
 extern const char *drbd_buildtag(void);
-#define REL_VERSION "8.3.8"
+#define REL_VERSION "8.3.8.1"
 #define API_VERSION 88
 #define PRO_VERSION_MIN 86
 #define PRO_VERSION_MAX 94
diff --git a/include/linux/drbd_nl.h b/include/linux/drbd_nl.h
index ce77a74..5f04281 100644
--- a/include/linux/drbd_nl.h
+++ b/include/linux/drbd_nl.h
@@ -78,10 +78,11 @@
 	NL_INTEGER(	30,	T_MAY_IGNORE,	rate)
 	NL_INTEGER(	31,	T_MAY_IGNORE,	after)
 	NL_INTEGER(	32,	T_MAY_IGNORE,	al_extents)
-	NL_INTEGER(     71,	T_MAY_IGNORE,	dp_volume)
-	NL_INTEGER(     72,	T_MAY_IGNORE,	dp_interval)
-	NL_INTEGER(     73,	T_MAY_IGNORE,	throttle_th)
-	NL_INTEGER(     74,	T_MAY_IGNORE,	hold_off_th)
+/*	NL_INTEGER(     71,	T_MAY_IGNORE,	dp_volume)
+ *	NL_INTEGER(     72,	T_MAY_IGNORE,	dp_interval)
+ *	NL_INTEGER(     73,	T_MAY_IGNORE,	throttle_th)
+ *	NL_INTEGER(     74,	T_MAY_IGNORE,	hold_off_th)
+ * feature will be reimplemented differently with 8.3.9 */
 	NL_STRING(      52,     T_MAY_IGNORE,   verify_alg,     SHARED_SECRET_MAX)
 	NL_STRING(      51,     T_MAY_IGNORE,   cpu_mask,       32)
 	NL_STRING(	64,	T_MAY_IGNORE,	csums_alg,	SHARED_SECRET_MAX)