diff --git a/sys/dev/cxgbe/cxgbei/icl_cxgbei.c b/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
--- a/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
+++ b/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
@@ -104,6 +104,12 @@
 
 SYSCTL_NODE(_kern_icl, OID_AUTO, cxgbei, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
     "Chelsio iSCSI offload");
+static int first_burst_length = 8192;
+SYSCTL_INT(_kern_icl_cxgbei, OID_AUTO, first_burst_length, CTLFLAG_RWTUN,
+    &first_burst_length, 0, "First burst length");
+static int max_burst_length = 2 * 1024 * 1024;
+SYSCTL_INT(_kern_icl_cxgbei, OID_AUTO, max_burst_length, CTLFLAG_RWTUN,
+    &max_burst_length, 0, "Maximum burst length");
 static int sendspace = 1048576;
 SYSCTL_INT(_kern_icl_cxgbei, OID_AUTO, sendspace, CTLFLAG_RWTUN,
     &sendspace, 0, "Default send socket buffer size");
@@ -1206,8 +1212,8 @@
 	idl->idl_max_send_data_segment_length = (1 << 24) - 1;
 
 	/* These are somewhat arbitrary. */
-	idl->idl_max_burst_length = 2 * 1024 * 1024;
-	idl->idl_first_burst_length = 8192;
+	idl->idl_max_burst_length = max_burst_length;
+	idl->idl_first_burst_length = first_burst_length;
 
 	t4_iterate(cxgbei_limits, idl);