We don't have an oil light ...... that extra bulb position has been empty for like 20 years now. Some folks have rigged an oil pressure sensor, but we don't have enough idle oil pressure to light it up repeat-ably.
If you are worried about oil level, see
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1358048782/11#11If you are worried about oil pressure, run your idle speed up at 1,000 rpm (a fast even idle) which will keep your oil pressure up at 4-6 psi all the time. This is good for your cam bearing journals, which need oil pressure to live a nice full life.
DO NOT DO A LUMPY SOUNDING SLOW "harley style" idle -- you own a jap bike, not a harley.