[Info-vax] Raxco VMS Tuning Seminar Notes

[jls]

On 3 Nov 2010 16:33:45 -0600, koehler at eisner.nospam.encompasserve.org
(Bob Koehler) wrote:

>In article <gr73d61ue65tf9uiv65fhdu6mg8ihqad8f at 4ax.com>, jls <notvalid at yahoo.com> writes:
>> 
>> PFRATL does not trim idle processes.  It is a quantum-driven memory
>> management technique and idle processes do not reach quantum end.
>
>   So they eithre got trimmed before they went idle, or when my process
>   watcher called $GETJPI, which queues an AST to them.

If they get paged down to swpoutpgcnt, then when they become active
again, they will have to page in each page separately, and if these
are hard faults, it will be one I/O for each page.

And if you're using other mechanisms to reclaim memory, why use
PFRATL?  The interaction between PFRATL and PFRATH almost insures that
active processes will thrash pages in and out.  That does not help
performance.