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From: Tommy_Ericson_QZ@QZCOM.MAILNET
Newsgroups: mod.computers.vax
Subject: PFRATL = 0 or > 0 ?
Message-ID: <189475@QZCOM>
Date: Fri, 25-Jul-86 09:08:35 EDT
Article-I.D.: QZCOM.189475
Posted: Fri Jul 25 09:08:35 1986
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Is there anybody out there who has done some investigations about
the a) overall system effects b) user response when having PFRATL=0
and PFRATL>0 (e.g. 1)?  We have the feeling that PFRATL=0 is
to be preferred only if primary memory is not fully committed,
but that PFRATL=1 gives positive effects on both a) and b) when
memory is overcommitted.

While on the topic: having PFRATL=1 and plenty of free memory,
VMS still reduces phys mem for processes, thus forcing them to
unnecessary page-faults (although in core). I would suggest that
there was a SYSGEN parameter (unit: Pages) with the semantics
"do not reduce process memory allocation if free memory is higher
than this value", i.e. in effect PFRATL=0. Isn't this actually
how the swapper is supposed to work? I cannot see any drawback
with this.