RE: Memory pool trivia

[Chris Bipes <chris.bipes@xxxxxxxxxxxxxxx>]

See inline answers:

Christopher K. Bipes
Information Services Director
CrossCheck, Inc.


-----Original Message-----
From: Haase, Justin C. [mailto:justin.haase@xxxxxxxxxxxx] 
Sent: Friday, April 22, 2005 1:50 PM
To: Midrange Systems Technical Discussion
Subject: Memory pool trivia


Ok folks - I'm looking for the answer to a question (below), but I'm not
finding a definitive result anywhere and would like some feedback on it.

When looking at a WRKSYSSTS screen and looking at a memory pool, let's use
this as an example:

Sys      Pool   Reserved    Max  ----DB-----  --Non-DB---  Act-   Wait-
Act- 
Pool    Size M   Size M     Act  Fault Pages  Fault Pages  Wait   Inel
Inel 
  3     267.17       .00     90     .0    .0     .5    .6   23.5     .0
.0

The pool size is the amount of memory currently assigned, and the Max Act is
the maximum number of threads which can run at any one moment in that pool.
If more than 90 threads are trying, you'll get WAIT->INEL and ACT->INEL with
the active to ineligible being the worst of the two - both are bad, but
active to ineligible is worse.  Correct so far?

Yes.

**My question is:  Does the system deal with the pool in such a way that
there are (in this example) 2.968555 MB of memory available to each thread,
no matter how many are running (pool size / max act), or if there's only one
thread active, will it allocate all 267.17 MB of memory to it?

No.  Each job will get the memory it needs.  If there is not enough memory
available for all the threads running in the pool, you will get Non-DB
pages.  Inactive threads will be paged out first followed by un-needed
portions of active threads.