AIX

AIX

Connect with fellow AIX users and experts to gain knowledge, share insights, and solve problems.

 View Only

  • 1.  when page replacement is invoked in aix?

    Posted Mon July 21, 2008 04:45 AM

    Originally posted by: SystemAdmin


    "When the number of free page frames gets to a low value, the AIX kernel must empty out some locations in real memory for reuse of new pages. This process is otherwise known as page replacement.The AIX VMM has background daemons responsible for doing page replacement. "
    Can we conclude that if free frames are always enough(suppose the real memory is large enough) ,the page replacement daemon is never invoked.

    I did some test find this phenmenon: when free frames are more than the maxfree, there are still page in and page out through the command vmstat. At this time , the number of non-computational page is small (the numperm is less than minperm).

    Anybody can explain this? thanks a lot!


  • 2.  Re: when page replacement is invoked in aix?

    Posted Mon July 21, 2008 10:31 AM

    Originally posted by: MarkTaylor


    That would wholly depend on your lru_file_repage, maxperm, maxclient, minfree, strict_maxclient and strict_maxperm settings, oh and number of lrud buckets / size etc ..

    free pages being greater than maxfree is not an algorythm used by AIX lru !! maxfree is the number of pages that lrud tries to place back on the freelist once minfree pages are reached on the freelist.


Related Content