Your mystification is apparently due to poor memory. I suggest that you review the archives for the subject:: REFRPROT History Question, a thread which you started on March 1, 2013.
In particular, see my answers in https://listserv.ua.edu/cgi-bin/wa?A2=ind1303&L=IBM-MAIN&P=R2798&I=-3&X=-&Y=d10jhm1%40us.ibm.com&d=No+Match%3BMatch%3BMatches And there is a performance cost for the page-protecting aspect of REFRPROT. Turning on the protection bit in the PTE for a page that is already valid requires some type of broadcast TLB purging operation. We accomplish this by doing an IPTE to invalidate the page before turn on the protection bit. Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY IBM Mainframe Discussion List <[email protected]> wrote on 06/10/2017 10:54:15 AM: > From: Paul Gilmartin <[email protected]> > To: [email protected] > Date: 06/10/2017 09:55 PM > Subject: Re: APF authorization and AC(00) > Sent by: IBM Mainframe Discussion List <[email protected]> > > On Sat, 10 Jun 2017 07:27:15 -0400, Peter Relson wrote: > > >>REFRPROT extends this to programs that are not loaded from an > >>APF authorized library. > > > >Actually, REFRPROT extends this to programs that are bound with the REFR > >option regardless of module authorization or library authorization. > >And it goes further because it page-protects, which would cause the > >program to blow up even if were running key 0 if it attempted to store > >into itself. > > > I remain mystified, Why was not the REFRPROT behavior the default > (or only) behavior ever since the inception of the REFR attribute? > o Is there a performance penalty for REFRPROT that developers > wanted to circumvent for problem programs? Contrariwise, it seems > that coding a test for the authorized status of the load library was > needless effort. > o Did the developers assume, very incorrectly IMO, that they were > extending a courtesy to application programmers by permitting > programs that modified themselves to be marked REFR? > > -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
