Re: Linkage convention

Article View: bit.listserv.asm370

Article #203

Back to bit.listserv.asm370 Previous Next

#203

From: Craddock, Chris
Date: Mon, 17 Oct 2005 16:40

38 lines
3533 bytes

> The GETMAIN code has been rock solid for decades, and has also been
> highly optimized in its execution paths.

Well yes, that's basically true. However, it is also true that GETMAIN
and its cousins are among the most expensive system functions in terms
of raw instruction path length. They are heavy on serialization and on
searching the various structures used for accounting and managing
virtual storage.

> If you need to do tens  of thousands of GETMAINs per second in
disabled
> code, then maybe you  might want to think about eliminating them.

Disabled code can only obtain or release page-fixed, or disabled
reference common storage. Doing any more than the barest, of bare
minimum storage management, while running disabled, is an utterly
appalling idea.

> But if you have well-debugged infrastructure code to use software
stacks,
> by all means use it.  But don't bother trying to build  your own such
> code. I don't think it's worth the  development/debug/support effort.

The funny thing is, everyone who finds themselves in the business of
writing software that runs in these sorts of environments DOES end up
writing some form of stack management infrastructure, or they wear the
cost of less-than-stellar performance.

> And you can reduce the overhead of  GETMAINs by using the PC entry
form
> rather than the SVC form.

Paradoxically, even though a PC is a lot faster than an SVC, the STORAGE
macro supports a lot more flexible entry conditions and does a lot more
state checking than GETMAIN and as a result it is slightly (but
measurably) slower than GETMAIN.

CC

Technical Details

Message-ID: <E9DE7963E5EA6546B42A979EC28B4D011565DD18@hou-ex-02.adprod.bmc.com>

Path:

arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!wns14feed!worldnet.att.net!4.24.21.153!newsfeed3.dallas1.level3.net!news.level3.com!newsfeed1.easynews.com!easynews.com!easynews!sn-xit-02!sn-xit-12!sn-xit-09!sn-xit-06!sn-xit-14!supernews.com!149.173.6.116.MISMATCH!foggy!vm.sas.com!bmc.com!Chris_Craddock

Show Full Headers

Complete Article Headers

X-Google-Thread: fcdcb,91cbe6b24531a1d8
X-Google-Attributes: gidfcdcb,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!wns14feed!worldnet.att.net!4.24.21.153!newsfeed3.dallas1.level3.net!news.level3.com!newsfeed1.easynews.com!easynews.com!easynews!sn-xit-02!sn-xit-12!sn-xit-09!sn-xit-06!sn-xit-14!supernews.com!149.173.6.116.MISMATCH!foggy!vm.sas.com!bmc.com!Chris_Craddock
From: "Craddock, Chris" <Chris_Craddock@bmc.com>
Newsgroups: bit.listserv.asm370
Subject: Re: Linkage convention
Date: Mon, 17 Oct 2005 11:40:23 -0500
Organization: SAS Inc.
Lines: 38
Sender: IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU>
Message-ID: <E9DE7963E5EA6546B42A979EC28B4D011565DD18@hou-ex-02.adprod.bmc.com>
NNTP-Posting-Host: mozart.unx.sas.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Trace: foggy.unx.sas.com 1129567579 30316 10.19.150.41 (17 Oct 2005 16:46:19 GMT)
X-Complaints-To: usenet@unx.sas.com
NNTP-Posting-Date: Mon, 17 Oct 2005 16:46:19 +0000 (UTC)
Comments: Gated by NETNEWS@VM.SAS.COM
Return-Path: <owner-assembler-list@LISTSERV.UGA.EDU>
X-MimeOLE: Produced By Microsoft Exchange V6.0.6603.0
Content-class: urn:content-classes:message
Thread-Topic: Re: Linkage convention
Thread-Index: AcXTNdks+mQRcI/MTzGOwH8ib01lrgAAkPuw
X-OriginalArrivalTime: 17 Oct 2005 16:40:24.0666 (UTC)
                       FILETIME=[79016BA0:01C5D339]
X-Spamicity: Yes, tests=bogofilter, spamicity=1.000000, version=0.94.14
X-MIME-Autoconverted: from quoted-printable to 8bit by listserv.cc.uga.edu id
                      j9HGeVld029831
Approved-By: "Craddock, Chris" <Chris_Craddock@BMC.COM>
Return-Path: owner-assembler-list@LISTSERV.UGA.EDU
X-Mime-Autoconverted: from 8bit to 7bit by mime827
Originator: daemon@mozart.unx.sas.com