Is answered in the PDF which Doug Henry specified: http://www-03.ibm.com/servers/enable/site/education/wp/1d71a/1d71a.pdf
<quote> APAR OA26294 provides a direct assembler interface to z/OS Real Storage Manager (RSM), which allows memory allocations in the 2 GB (2^31) to 32 GB (2^35) virtual address range. The IBM JVM uses this API to allocate the Java heap in this virtual address range. It is noted that memory allocated using the RSM API can be backed by either 4 KB pages or large pages. </quote> Why 2^35 (32G)? Because that is the upper limit on Java's heap for using "compressed pointers". Above 32G of heap, Java does not compress pointers. 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
