Index: cam/cam_xpt_sim.h
===================================================================
--- cam/cam_xpt_sim.h	(revision 228936)
+++ cam/cam_xpt_sim.h	(working copy)
@@ -51,6 +51,8 @@
 		    u_int count, int run_queue);
 int		xpt_sim_opened(struct cam_sim *sim);
 void		xpt_done(union ccb *done_ccb);
+void		xpt_batch_start(struct cam_sim *sim);
+void		xpt_batch_done(struct cam_sim *sim);
 #endif
 
 #endif /* _CAM_CAM_XPT_SIM_H */
Index: cam/cam_sim.h
===================================================================
--- cam/cam_sim.h	(revision 228936)
+++ cam/cam_sim.h	(working copy)
@@ -106,6 +106,7 @@
 #define	CAM_SIM_MPSAFE			0x02
 #define	CAM_SIM_ON_DONEQ		0x04
 #define	CAM_SIM_POLLED			0x08
+#define	CAM_SIM_BATCH			0x10
 	struct callout		callout;
 	struct cam_devq 	*devq;	/* Device Queue to use for this SIM */
 	int			refcount; /* References to the SIM. */
Index: cam/cam_xpt.c
===================================================================
--- cam/cam_xpt.c	(revision 228936)
+++ cam/cam_xpt.c	(working copy)
@@ -4232,7 +4232,8 @@
 		TAILQ_INSERT_TAIL(&sim->sim_doneq, &done_ccb->ccb_h,
 		    sim_links.tqe);
 		done_ccb->ccb_h.pinfo.index = CAM_DONEQ_INDEX;
-		if ((sim->flags & (CAM_SIM_ON_DONEQ | CAM_SIM_POLLED)) == 0) {
+		if ((sim->flags & (CAM_SIM_ON_DONEQ | CAM_SIM_POLLED |
+		    CAM_SIM_BATCH)) == 0) {
 			mtx_lock(&cam_simq_lock);
 			first = TAILQ_EMPTY(&cam_simq);
 			TAILQ_INSERT_TAIL(&cam_simq, sim, links);
@@ -4244,6 +4245,25 @@
 	}
 }
 
+void
+xpt_batch_start(struct cam_sim *sim)
+{
+
+	KASSERT((sim->flags & CAM_SIM_BATCH) == 0, ("Batch flag already set"));
+	sim->flags |= CAM_SIM_BATCH;
+}
+
+void
+xpt_batch_done(struct cam_sim *sim)
+{
+
+	KASSERT((sim->flags & CAM_SIM_BATCH) != 0, ("Batch flag was not set"));
+	sim->flags &= ~CAM_SIM_BATCH;
+	if (!TAILQ_EMPTY(&sim->sim_doneq) &&
+	    (sim->flags & CAM_SIM_ON_DONEQ) == 0)
+		camisr_runqueue(&sim->sim_doneq);
+}
+
 union ccb *
 xpt_alloc_ccb()
 {
Index: dev/siis/siis.c
===================================================================
--- dev/siis/siis.c	(revision 228936)
+++ dev/siis/siis.c	(working copy)
@@ -830,7 +830,9 @@
 	struct siis_channel *ch = device_get_softc(dev);
 
 	mtx_lock(&ch->mtx);
+	xpt_batch_start(ch->sim);
 	siis_ch_intr(data);
+	xpt_batch_done(ch->sim);
 	mtx_unlock(&ch->mtx);
 }
 
Index: dev/ahci/ahci.c
===================================================================
--- dev/ahci/ahci.c	(revision 228936)
+++ dev/ahci/ahci.c	(working copy)
@@ -1456,7 +1456,9 @@
 	struct ahci_channel *ch = device_get_softc(dev);
 
 	mtx_lock(&ch->mtx);
+	xpt_batch_start(ch->sim);
 	ahci_ch_intr(data);
+	xpt_batch_done(ch->sim);
 	mtx_unlock(&ch->mtx);
 }
 
Index: dev/mvs/mvs.c
===================================================================
--- dev/mvs/mvs.c	(revision 228936)
+++ dev/mvs/mvs.c	(working copy)
@@ -654,7 +654,9 @@
 	struct mvs_channel *ch = device_get_softc(dev);
 
 	mtx_lock(&ch->mtx);
+	xpt_batch_start(ch->sim);
 	mvs_ch_intr(data);
+	xpt_batch_done(ch->sim);
 	mtx_unlock(&ch->mtx);
 }
 
Index: dev/ata/ata-all.c
===================================================================
--- dev/ata/ata-all.c	(revision 228936)
+++ dev/ata/ata-all.c	(working copy)
@@ -532,9 +532,11 @@
     struct ata_channel *ch = (struct ata_channel *)data;
 
     mtx_lock(&ch->state_mtx);
+    xpt_batch_start(ch->sim);
 #endif
     ata_interrupt_locked(data);
 #ifdef ATA_CAM
+    xpt_batch_done(ch->sim);
     mtx_unlock(&ch->state_mtx);
 #endif
 }