Index: sys/cam/ata/ata_da.c
===================================================================
--- sys/cam/ata/ata_da.c
+++ sys/cam/ata/ata_da.c
@@ -805,7 +805,8 @@
 	}
 
 	if (length > 0) {
-		xpt_setup_ccb(&ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+		xpt_setup_ccb_flags(&ccb.ccb_h, periph->path,
+		    CAM_PRIORITY_NORMAL, 0, CAM_CCB_DUMP);
 		ccb.ccb_h.ccb_state = ADA_CCB_DUMP;
 		cam_fill_ataio(&ccb.ataio,
 		    0,
@@ -839,7 +840,8 @@
 	}
 
 	if (softc->flags & ADA_FLAG_CAN_FLUSHCACHE) {
-		xpt_setup_ccb(&ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+		xpt_setup_ccb_flags(&ccb.ccb_h, periph->path,
+		    CAM_PRIORITY_NORMAL, 0, CAM_CCB_DUMP);
 
 		ccb.ccb_h.ccb_state = ADA_CCB_DUMP;
 		cam_fill_ataio(&ccb.ataio,
Index: sys/cam/cam_ccb.h
===================================================================
--- sys/cam/cam_ccb.h
+++ sys/cam/cam_ccb.h
@@ -112,7 +112,8 @@
 typedef enum {
 	CAM_USER_DATA_ADDR	= 0x00000002,/* Userspace data pointers */
 	CAM_SG_FORMAT_IOVEC	= 0x00000004,/* iovec instead of busdma S/G*/
-	CAM_UNMAPPED_BUF	= 0x00000008 /* use unmapped I/O */
+	CAM_UNMAPPED_BUF	= 0x00000008,/* use unmapped I/O */
+	CAM_CCB_DUMP		= 0x00000010,/* used for dump I/O */
 } ccb_xflags;
 
 /* XPT Opcodes for xpt_action */
Index: sys/cam/cam_xpt.c
===================================================================
--- sys/cam/cam_xpt.c
+++ sys/cam/cam_xpt.c
@@ -165,6 +165,7 @@
 };
 
 static struct cam_doneq cam_doneqs[MAXCPU];
+static struct cam_doneq cam_dumpq;
 static int cam_num_doneqs;
 static struct proc *cam_proc;
 
@@ -256,7 +257,8 @@
 static xpt_devicefunc_t xptpassannouncefunc;
 static void	 xptaction(struct cam_sim *sim, union ccb *work_ccb);
 static void	 xptpoll(struct cam_sim *sim);
-static void	 camisr_runqueue(void);
+static void	 camisr_runqueue(struct cam_doneq *queue);
+static void	 camisr_runqueues(void);
 static void	 xpt_done_process(struct ccb_hdr *ccb_h);
 static void	 xpt_done_td(void *);
 static dev_match_ret	xptbusmatch(struct dev_match_pattern *patterns,
@@ -928,6 +930,8 @@
 		       "- failing attach\n");
 		return (ENOMEM);
 	}
+	mtx_init(&cam_dumpq.cam_doneq_mtx, "CAM dumpq", NULL, MTX_DEF);
+	STAILQ_INIT(&cam_dumpq.cam_doneq);
 	/*
 	 * Register a callback for when interrupts are enabled.
 	 */
@@ -3036,7 +3040,7 @@
 		CAM_SIM_LOCK(sim);
 		(*(sim->sim_poll))(sim);
 		CAM_SIM_UNLOCK(sim);
-		camisr_runqueue();
+		camisr_runqueues();
 		mtx_lock(&devq->send_mtx);
 	}
 	dev->ccbq.dev_openings++;
@@ -3048,9 +3052,9 @@
 			CAM_SIM_LOCK(sim);
 			(*(sim->sim_poll))(sim);
 			CAM_SIM_UNLOCK(sim);
-			camisr_runqueue();
-			if ((start_ccb->ccb_h.status  & CAM_STATUS_MASK)
-			    != CAM_REQ_INPROG)
+			camisr_runqueues();
+			if ((start_ccb->ccb_h.status & CAM_STATUS_MASK) !=
+			    CAM_REQ_INPROG)
 				break;
 			DELAY(100);
 		}
@@ -4439,9 +4443,13 @@
 	if ((done_ccb->ccb_h.func_code & XPT_FC_QUEUED) == 0)
 		return;
 
-	hash = (done_ccb->ccb_h.path_id + done_ccb->ccb_h.target_id +
-	    done_ccb->ccb_h.target_lun) % cam_num_doneqs;
-	queue = &cam_doneqs[hash];
+	if (__predict_false((done_ccb->ccb_h.xflags & CAM_CCB_DUMP) != 0))
+		queue = &cam_dumpq;
+	else {
+		hash = (done_ccb->ccb_h.path_id + done_ccb->ccb_h.target_id +
+		    done_ccb->ccb_h.target_lun) % cam_num_doneqs;
+		queue = &cam_doneqs[hash];
+	}
 	mtx_lock(&queue->cam_doneq_mtx);
 	run = (queue->cam_doneq_sleep && STAILQ_EMPTY(&queue->cam_doneq));
 	STAILQ_INSERT_TAIL(&queue->cam_doneq, &done_ccb->ccb_h, sim_links.stqe);
@@ -5272,22 +5280,31 @@
 }
 
 static void
-camisr_runqueue(void)
+camisr_runqueue(struct cam_doneq *queue)
 {
-	struct	ccb_hdr *ccb_h;
-	struct cam_doneq *queue;
-	int i;
+	struct ccb_hdr *ccb_h;
 
-	/* Process global queues. */
-	for (i = 0; i < cam_num_doneqs; i++) {
-		queue = &cam_doneqs[i];
-		mtx_lock(&queue->cam_doneq_mtx);
-		while ((ccb_h = STAILQ_FIRST(&queue->cam_doneq)) != NULL) {
-			STAILQ_REMOVE_HEAD(&queue->cam_doneq, sim_links.stqe);
-			mtx_unlock(&queue->cam_doneq_mtx);
-			xpt_done_process(ccb_h);
-			mtx_lock(&queue->cam_doneq_mtx);
-		}
+	mtx_lock(&queue->cam_doneq_mtx);
+	while ((ccb_h = STAILQ_FIRST(&queue->cam_doneq)) != NULL) {
+		STAILQ_REMOVE_HEAD(&queue->cam_doneq, sim_links.stqe);
 		mtx_unlock(&queue->cam_doneq_mtx);
+		xpt_done_process(ccb_h);
+		mtx_lock(&queue->cam_doneq_mtx);
 	}
+	mtx_unlock(&queue->cam_doneq_mtx);
+}
+
+static void
+camisr_runqueues(void)
+{
+	int i;
+
+	if (dumping) {
+		camisr_runqueue(&cam_dumpq);
+		return;
+	}
+
+	/* Process global queues. */
+	for (i = 0; i < cam_num_doneqs; i++)
+		camisr_runqueue(&cam_doneqs[i]);
 }
Index: sys/cam/scsi/scsi_da.c
===================================================================
--- sys/cam/scsi/scsi_da.c
+++ sys/cam/scsi/scsi_da.c
@@ -1482,7 +1482,8 @@
 	}
 
 	if (length > 0) {
-		xpt_setup_ccb(&csio.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+		xpt_setup_ccb_flags(&csio.ccb_h, periph->path,
+		    CAM_PRIORITY_NORMAL, 0, CAM_CCB_DUMP);
 		csio.ccb_h.ccb_state = DA_CCB_DUMP;
 		scsi_read_write(&csio,
 				/*retries*/0,
@@ -1515,7 +1516,8 @@
 	 */
 	if ((softc->quirks & DA_Q_NO_SYNC_CACHE) == 0) {
 
-		xpt_setup_ccb(&csio.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+		xpt_setup_ccb_flags(&csio.ccb_h, periph->path,
+		    CAM_PRIORITY_NORMAL, 0, CAM_CCB_DUMP);
 		csio.ccb_h.ccb_state = DA_CCB_DUMP;
 		scsi_synchronize_cache(&csio,
 				       /*retries*/0,