> -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:ibm-m...@bama.ua.edu] On Behalf Of Edward Jaffe > Sent: Friday, January 01, 2010 10:42 AM > To: IBM-MAIN@bama.ua.edu > Subject: Re: dead zone > > Steve Samson <ssam...@dc.rr.com> writes: > >> The "bar" is a thick one, from 2g to 4g, "sacrificed" to avoid a > >> somewhat unlikely compatibility exposure. Undisciplined use of the > >> high-order bit in 31-bit addresses could have led to unexpected > >> results. The thick bar avoids such a problem. Considering the vast > >> magnitude of 64-bit virtual addresses, why should anyone care or do > >> anything to circumvent the omitted address range? > >> > > The z/OS RSM developers introduced functionality to allow Java to > acquire storage within the previously "thick" bar for > performance reasons. > > -- > Edward E Jaffe
Hum, that is very curious to me. But I guess it expands the available/addressable storage without switching from AMODE(31) to AMODE(64) and back. Java is a storage pig. And too much stuff in z/OS still requires AMODE(31) storage (like DCBs et al.) -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * (817)-961-6183 cell john.mck...@healthmarkets.com * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
