Multicore support - suggest limit to number of threads

[mael_dc]

I recently upgraded to a 24-core machine and had to disable the multicore feature.   

WIth multicore enabled, CFSM kicks off 24 threads when it scans  (this takes a while).  Then, if I need to repair a single song it runs the repair on one thread and then the other 23 threads run with "nothing to do".   This also takes a while.

With so many cores I''ve found that a full scan takes longer with multicore enabled than running single threaded.

Can you consider adding a parameter that will limit the number of threads that run with multicore enabled?