if you are sure the core is still sealed off by the remaining basematerial, you shouldn't worry...
you could repair it yourself with a repair-candle or bring it to a shop and have it filled when you have time ...
however if the core would be exposed and you'd have a "real" coreshot you shouldn't ski it before its repaired and your core is sealed again, otherwise moisture will soak into your core and could cause your ski to break eventually ....
if the cut is very deep you're better off having a shop repair it, repaircandles can handle it, but it's more difficult to repair deep scratches and it's les strong then when a shop repairs it with a ptex gun ...
and don't worry about performance, i'm quite sure that if you would put on your skis randomly you wouldn't even feel the difference between the damaged ski and the good one ...
a few scratches don't influence performance noticeably...
