On Fri, 5 Jun 2009 11:54:29 -0500, McKown, John wrote: >> -----Original Message----- >> From: IBM Mainframe Discussion List >> [mailto:[email protected]] On Behalf Of Paul Gilmartin >> Sent: Friday, June 05, 2009 10:34 AM >> To: [email protected] >> Subject: Re: EXEC Above the Bar (Was Large Page Support) >> >> On Thu, 4 Jun 2009 18:33:35 -0500, Rick Fochtman wrote: >> >> >Jim, a completely different question: can you give us any >> idea or hint >> >when we can expect to use executable code above the bar? >> > >> Dream on. >> >> But it must happen, sooner or later. >> >> But IBM might not preannounce it. >> >> >In my shop, we have programs that are executed literally thousands of >> >times per day and program fetch is a significant part of the time >> >involved. Adding these programs to LPA/ELPA/MLPA/EMLPA isn't >> practical >> >because of private area impacts, especially with DB2 and IDMS. >> > >> A while back I asked on this list whether the below-the-bar >> restriction >> of LPA was being felt as constraining. Apparently, now, the answer >> is "yes". >> >> Can Java byte code be kept in LPA? > >Java byte code is not executable. I.e., not a LoadModule or a >ProgramObject. From a z/OS viewpoint, it is data. So, I doubt >that it could be loaded into LPA. Now, [E]CSA? probably. Maybe >even HVCOMMON. > >> >> Can Java byte code be loaded above the bar? > >Can't say for sure, but with the 64-bit JVM, why not? The JVM >itself resides in 31-bit storage, as would any JIT compiled code, >but the byte code is data in the z/OS sense, > >> >> I could see a use for load modules marked RMODE(64),OL, and >> even for an enhanced LPA to support sharing them, without >> the requirement for TCB, RB, etc. support. > >That might be the "first" to be implemented. For large, shared, >read-only data tables.
Maybe so.... From the z/OS 1.11 preview: "In z/OS V1.11, support is added for data tables contained in load modules and program objects to be placed above 2 GB. A new ADDR64 parameter on the LOAD macro supports loading load modules and program objects containing only data tables above the bar. This function is intended to help relieve virtual storage constraints by allowing data tables to be loaded above the bar." -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
