[Info-vax] Raxco VMS Tuning Seminar Notes

[jls]

On Mon, 8 Nov 2010 16:49:22 -0800 (PST), AEF <spamsink2001 at yahoo.com>
wrote:

>On Nov 8, 3:06 pm, jls <notva... at yahoo.com> wrote:
>> On 3 Nov 2010 16:33:45 -0600, koeh... at eisner.nospam.encompasserve.org
>>
>> (Bob Koehler) wrote:
>> >In article <gr73d61ue65tf9uiv65fhdu6mg8ihqa... at 4ax.com>, jls <notva... 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.
>
>I recall that the manuals say that swapping is a very expensive
>operation I/O wise. Am I missing something here?

Old info - probably pre-V4.x.

>
>That's why there's
>
>3.7 Active Memory Reclamation from Idle Processes
>

Which is fine as far as it goes, but if you page out lots of process
pages, eventually the process will become active and those pages will
be hardfaulted back in, one at a time.

Again I reiterate - the swapper will bring in the entire process in
ONE I/O.