IMHO this shouldnt be a problem. My last vacation I was in India for 2 months and never even thought that the Swiss Immigrations should have a problem with my vacation!
But the only thing you need to make sure is be here when your permit is up for renewal and ofcourse it goes without saying that if your L permit expires when you are on vacation you are going to really complicate the renewal!
Have a nice vacation.
PS:If you think that you will be very certain if some officials answer you for this,then I suggest you to go to the local geminde and ask them.