Why is the real address relevant? It's the virtual address that's in the PLIST.
I have no objection to permanently making the last page reserved. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of Ed Jaffe <[email protected]> Sent: Saturday, September 5, 2020 11:31 AM To: [email protected] Subject: Re: Deep cuts On 9/4/2020 10:46 AM, Seymour J Metz wrote: > VM uses a token of 8X'FF' at the end of the (R1) parameter list. I don't > recall what the convention is for the (R0) extended parameter list introduced > by VM/SP. We've adopted "eight bytes of foxes" as an end marker for variable-length parameter lists that use 64-bit pointers. Of course, we realize it means we have a permanent restriction that the singular byte address of "sixteen exabytes minus one" cannot be passed unambiguously as a parameter in such parameter lists. We really don't see that as posing any practical problem for our software even if that byte is available for acquisition. We're also sort of assuming RSM will never hand out the last 1M or perhaps even 2G virtual in a manner similar to what's done today for the 4K page at x'7FFFF000'. -- Phoenix Software International Edward E. Jaffe 831 Parkview Drive North El Segundo, CA 90245 https://secure-web.cisco.com/1U01JRZQw9X_XdcydI-WdlLK9XIvyv-71xrVaeQ0HN69bO1-Asg7FJoVKEtu0dw-D0tDjY3ID-qG7ORT_nXAxmlJArzsppbRS2HRQQylZHnBcwzuJxAC7LzozM4KMiRDSsvht1G3-GIk6GM8JpuWhHJHqlF8kbwhJzavatoltYrYwZ-T-r394dd-ko2xSJWe59MMkmT4QXQL1Oa9ATrmX-KlxZHvXt3ePa-sGrWrnIIwzc7t50pi6tpTo90-_8h6cHxTIc2mIPcCCZPMMUXB_hwPdNRHDQIkB2kAWYl0xS382IwIj790bqhkclDkCGNWXEYaIBdMt94pD441gqH0KpTqGhDREm0zdPO2yPtZQmQi8FOizU_xpFVhf3jdqOX2xtPkxEuPk9nf2f9G3tSDlPyl0l_dZrmgXNHbJVbDvFKZRKRnROMHCV9Phgbuqxhnb/https%3A%2F%2Fwww.phoenixsoftware.com%2F -------------------------------------------------------------------------------- This e-mail message, including any attachments, appended messages and the information contained therein, is for the sole use of the intended recipient(s). If you are not an intended recipient or have otherwise received this email message in error, any use, dissemination, distribution, review, storage or copying of this e-mail message and the information contained therein is strictly prohibited. If you are not an intended recipient, please contact the sender by reply e-mail and destroy all copies of this email message and do not otherwise utilize or retain this email message or any or all of the information contained therein. Although this email message and any attachments or appended messages are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by the sender for any loss or damage arising in any way from its opening or use.
