Setting processor affinity

Discussion in 'Mac Basics and Help' started by Rhodan, May 9, 2007.

  1. Rhodan macrumors member

    May 9, 2007

    In Windows you can set applications to run on a specific cpu (processor affinity), I was wondering if you can do this in Mac OSX ?
  2. Rhodan thread starter macrumors member

    May 9, 2007
    Anyone of the 38 people who viewed the topic ?
  3. 4God macrumors 68020


    Apr 5, 2005
    My Mac
  4. nuclearwinter macrumors regular


    Nov 3, 2003
    Milky Way
    I seem to remember something about Apple's CHUD tools being able to do this. If memory serves, you can find this in the developer software included on the OS X install disc. Its under additional or optional software if I remember correctly. Let me know if that helps. I'd be interested in knowing what you find out.
  5. Rhodan thread starter macrumors member

    May 9, 2007
    I'm running Cisco router emulators that eats CPU's for breakfast, so I want to be able to assign specific router instances to a specific CPU.
  6. pilotError macrumors 68020


    Apr 12, 2006
    Long Island
    Last I heard, it couldn't do processor affinity.

    I would look for it in Leopard. Most of the Linux OS's had to change to deal with multi-core as well as multi-processor.
  7. Rhodan thread starter macrumors member

    May 9, 2007
    Damn that sucks, considering Winsuck can do it. Please check and let me know.
  8. savar macrumors 68000


    Jun 6, 2003
    District of Columbia
    Processor affinity means a process tends to run on a single processor, rather than getting randomly re-scheduled to other processors.

    The way Mac OS X currently works, if a process on core 1 gets stopped (for example, it's waiting for I/O), and while its stopped another process starts running on core 1, when the OS restarts the first process it might move it to core 2 since core 1 now appears busy.

    The problem with this is that each core has its own cache, and by moving a process between cores you lose all that cached information.

    To the original poster: 10.4 does not do this (although I guess some people claim it can be done with special tools), but I would expect that this almost definitely a feature in 10.5, especially since the whole line of CPUs is dual-core now.
  9. Rhodan thread starter macrumors member

    May 9, 2007
    Cool I hope so, are there any beta testers who can check this out ?
  10. cynikal macrumors member

    Aug 12, 2003

    has anyone figured this out?

    I'm trying to do RDMSR in ASM and need to bind the running process to direct the opcode to specific procs (albeit logical)..

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