Index: head/sys/vm/uma_core.c
===================================================================
--- head/sys/vm/uma_core.c
+++ head/sys/vm/uma_core.c
@@ -289,6 +289,7 @@
 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
 static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
 static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
+static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
 
 #ifdef INVARIANTS
 static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
@@ -1896,8 +1897,9 @@
 	oid = zone->uz_oid;
 	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
 	    "size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
-	SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
-	    "flags", CTLFLAG_RD, &zone->uz_flags, 0,
+	SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
+	    "flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
+	    zone, 0, sysctl_handle_uma_zone_flags, "A",
 	    "Allocator configuration flags");
 	SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
 	    "bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
@@ -4406,6 +4408,24 @@
 
 	cur = uma_zone_get_frees(zone);
 	return (sysctl_handle_64(oidp, &cur, 0, req));
+}
+
+static int
+sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
+{
+	struct sbuf sbuf;
+	uma_zone_t zone = arg1;
+	int error;
+
+	sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
+	if (zone->uz_flags != 0)
+		sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
+	else
+		sbuf_printf(&sbuf, "0");
+	error = sbuf_finish(&sbuf);
+	sbuf_delete(&sbuf);
+
+	return (error);
 }
 
 #ifdef INVARIANTS
Index: head/sys/vm/uma_int.h
===================================================================
--- head/sys/vm/uma_int.h
+++ head/sys/vm/uma_int.h
@@ -420,6 +420,32 @@
 #define	UMA_ZFLAG_INHERIT						\
     (UMA_ZFLAG_INTERNAL | UMA_ZFLAG_CACHEONLY | UMA_ZFLAG_BUCKET)
 
+#define	PRINT_UMA_ZFLAGS	"\20"	\
+    "\40CACHEONLY"			\
+    "\37TRASH"				\
+    "\36INTERNAL"			\
+    "\35BUCKET"				\
+    "\34RECLAIMING"			\
+    "\33CACHE"				\
+    "\22MINBUCKET"			\
+    "\21NUMA"				\
+    "\20PCPU"				\
+    "\17NODUMP"				\
+    "\16VTOSLAB"			\
+    "\15CACHESPREAD"			\
+    "\14MAXBUCKET"			\
+    "\13NOBUCKET"			\
+    "\12SECONDARY"			\
+    "\11HASH"				\
+    "\10VM"				\
+    "\7MTXCLASS"			\
+    "\6NOFREE"				\
+    "\5MALLOC"				\
+    "\4OFFPAGE"				\
+    "\3STATIC"				\
+    "\2ZINIT"				\
+    "\1PAGEABLE"
+
 #undef UMA_ALIGN
 
 #ifdef _KERNEL