Hi Gerd, I would expect the code to work on a MAC, because com.sun.management is part of the JDK, and defines the interface by which specific platforms can provide subinterfaces with further information (AFAIK there is only one for UNIX). However, I don't have a MAC, so can't test it on there. If it is a problem, I could take out that bit of code, which is just determining how much physical memory is installed, so that mkgmap won't suggest that the user increases the available heap too much. It isn't used in determining a value for maxjobs. Regards, Mike -----Original Message----- From: Gerd Petermann [mailto:gpetermann_muenchen@hotmail.com] Sent: 10 February 2018 15:45 To: mkgmap-dev@lists.mkgmap.org.uk Subject: Re: [mkgmap-dev] max-jobs patch Hi Mike, I've compiled r4107 with your patch: http://files.mkgmap.org.uk/download/418/mkgmap.jar I did not yet try it because I am still fighting with the crash in MapSource. I am not sure if the usage of classes like com.sun.management.OperatingSystemMXBean are supported with openjdk? Will this also work on a Mac? Gerd -- Sent from: http://gis.19327.n8.nabble.com/Mkgmap-Development-f5324443.html