On 7/5/2011 2:17 PM, Edward Jaffe wrote:
On 7/5/2011 10:28 AM, Paul Gilmartin wrote:
z/OS will be designed to support some programs running in 64-bit storage,
provided that they meet certain restrictions. This is intended to provide
virtual
"certain restrictions". Does this restrict ATB execution to contexts
such that the PSW needn't appear in a TCB or an RB, or will there
be support for unscrunched PSWs in those control blocks? (Or must
I wait for the full announcement?)
The operating system control blocks now handle 64-bit PSWs such that an
interrupt while executing above the bar is supported. No abend occurs.
WOW! That's a big deal.
Is this documented somewhere public? Or is this NDA?
Do you what the "certain restrictions" are? Can you tell us? Can
you tell us how it's done?
storage constraint relief to applications, particularly those that imbed code
in data areas for performance reasons.
Why would there be an advantage to imbedding code in data areas?
Sometimes this disrupts pipelining; the conventional wisdom is
to keep code and data in separate pages, isn't it? Does it
facilitate baseless coding?
It is often convenient to embed custom-generated code to handle custom-generated
data within the data itself. Without support for above-the-bar execution, such
programs would need to manage two areas for each data structure: one above the
bar and one below the bar. Of course, code and data must be in separate cache
lines.
--
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-Steve Comstock
The Trainer's Friend, Inc.
303-393-8716
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