Here is a sample of our code
USI200 DS 0H
L R7,SMFMEML ADDRESS OF MEMLIMIT PARMS
USING MEMLIMIT,R7 ESTABLISH ADDRESSABILITY
SPACE 1
SR R6,R6 CLEAR REG 6
L R6,SMFSSN ADDRESS OF THE SUBSYSTEM NAME
CLC 0(4,R6),=C'OMVS' IS IT SPAWNED BY OMVS?
BE RETURN IF YES, GET OUT QUICK
CLI MEMLFLGS,X'01' IS MEMLIMIT FROM SMF?
BE RETURN IF MEMLIMIT IS FROM SMF, GET OUT
CLI MEMLFLGS,X'FF' IS MEMLIMIT SOURCE IN ERROR ?
BE SETMEML IF MEMLIMIT IS IN ERROR, IMPOSE LIMIT
SR R6,R6 CLEAR REG 6
LG R6,MEMLSIZR LOAD MEMLIMIT SIZE REQUESTED INTO R6
CG R6,MEMABOVE COMPARE TO IEFUSI LIMITATION
BH SETMEML ASKING FOR MORE THAN LIMIT, GO RESET
STG R6,MEMLSIZU STORE USER REQUESTED MEMLIMIT
B RETURN BRANCH AROUND SETTING LIMITATION
SETMEML LG R6,MEMABOVE LOAD MEMLIMIT LIMITATION FOR STORING
STG R6,MEMLSIZU STORE IEFUSI IMPOSED MEMLIMIT
....
....
...
MEMABOVE DC XL8'00000800' MEMLIMIT - ABOVE 2G BAR LIMITATION = 2GB
* DOUBLE WORD HEX VALUE IN MB
SMFPARM DSECT
SMFPAREA DS F COMMON SMF PARAMETER AREA
SMFJSPNA DS A JOB STEP NAME
SMFPGMNA DS A PROGRAM NAME
SMFACCT DS A STEP ACCOUNTING INFORMATION
SMFVSMPL DS A VSM PARAMETER LIST
SMFVRFLG DS A ADDR OF V=R FLAG 8/89
SMFDSPCE DS A ADDR OF DATA SPACE INFORMATION 8/89
SMFSSN DS A ADDR OF SUBSYSTEM NAME 6/02
SMFMEML DS A ADDR OF MEMLIMIT PARMS 6/02
Jon L. Veilleux
[EMAIL PROTECTED]
(860) 636-2683
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Martin Packer
Sent: Sunday, December 09, 2007 12:26 PM
To: [email protected]
Subject: IEFUSI and 64 Bit - was "REGION=0M and LSQA"
Peter Relson wrote:
> While REGION=0M, in the absence of other things, does indicate not to
> reserve any particular amount for system subpools, many customers use
their
> IEFUSI exit to provide a limit to what REGION=0M can provide.
While I've not written a IEFUSI exit in MANY years (and even then only
as a sample, IIRC) I nowadays stress the importance of keeping control
of what users can allocate, ESPECIALLY in 64 bit mode. IEFUSI seems to
me the right way to do this (as well as with REGION, HVSHARE and
MEMLIMIT).
Anyone care to tell me what an installation would have to do to make
their "31-bit ready" IEFUSI into a "64-bit ready" one?
One thing I AM certain of is that allowing users to obtain huge amounts
of virtual and then to touch all the pages (perhaps mistakenly zeroing
them) is a great recipe for chaos.
Cheers, Martin
Martin Packer
Performance Consultant
IBM United Kingdom Ltd
+44-20-8832-5167
+44-7802-245-584
[EMAIL PROTECTED]
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number
741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6
3AU
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