stress2: Enable more swap disk usage

tools/test/stress2/misc/swap6.sh

@@ -33,7 +33,7 @@
 . ../default.cfg
 
 [ `sysctl -n vm.swap_total` -eq 0 ] && exit 0
-min=5	# percent swap usage
+min=10	# percent swap usage
 (cd ../testcases/swap; ./swap -t 10m -i 100 -l 100 -h > /dev/null) &
 sleep 1
 mx=0

tools/test/stress2/testcases/swap/swap.c

@@ -155,10 +155,8 @@ test(void)
 			c[i] = 0;
 			i += page;
 		}
-#if 0
-		if (op->hog != 1)
-			usleep(1000);
-#endif
+		if (arc4random() % 100 < 10)
+			usleep(10000);
 	}
 	free((void *)c);