On Thu, Feb 14, 2008 at 9:58 AM, Eduardo Sanz-Garcia <[EMAIL PROTECTED]> wrote: > Yes, I would be interested in an complete explanation of all those types > of memories.
Well, it works like this: OSX has 4 designations for memory, as you've seen: Wired, Active, Inactive, and Free. Wired memory is non-preemptable, must be resident at all times memory. Kernel memory, Root Page tables, stuff like that. Active memory is memory that is in use by a currently running application but can be paged out, application data, etc. Inactive memory is memory that was active within a certain time frame but is no longer in use. Seems weird, but there is a reason for this. One of which is that recently closed applications are likely to be used again in the near future. Said applications open much more quickly when all of their page tables are still in memory. Free memory is memory that has no claim, no nothing, just laying around waiting for something to need it. Free memory may be instantly taken by any application. Inactive memory has already been swapped out (if needed) and may be instantly taken by any application. Active memory must be swapped out, and thus can only be taken if there is no Free or Inactive memory which is less expensive to take. Wired memory can not be swapped or pre-empted. I have some slides for a presentation I did on this topic for CS 345. If you want them, let me know. -- Alex Esplin -------------------- BYU Unix Users Group http://uug.byu.edu/ The opinions expressed in this message are the responsibility of their author. They are not endorsed by BYU, the BYU CS Department or BYU-UUG. ___________________________________________________________________ List Info: http://uug.byu.edu/cgi-bin/mailman/listinfo/newbies
