I'm trying to set up a reasonable set of kernel params to support an
app. on a dedicated 4100 running DU4.0d, and need insight into the constraints
on them and relationship among them.
(1) It seems to me that:
max-per-proc-address space
should be equal to or greater than
max-per-proc-data-size + max-per-proc-stack-size + maxtsiz
Is this correct?
(2) I've gotten mixed info on the maximum value for max-per-proc-data-size -
one source within DEC told me it should not exceed the amount of physical
memory. Does anyone know if this is true?
(3) I've been told we need to be concerned with the value of vm-maxvas.
The definition I've found of this param. is that it is the max. virt. address
space for user maps - "see vm-mapentries".
vm-mapentries is defined as the maximum number of virtual memory map entries
a user map can have, and that map entries are allocated when the user maps
an object into virtual address space that:
1. is not adjacent to another object that has the same protection
and 2. can grow
and the default value for vm-mapentries is 200, but the default value for
vm-maxvas is "1L << 30" ??? which seems to be set to 1GB on our system.
What is the point of tuning this param - just how big *are* these mapentries?
Does it make any sense to increase it from 1GB????
(4) What other params would be affected by modifying these?
(5) Is it true that if max-per-proc-address-space is 1GB, then even if
there are multi-gigabytes of virtual memory a given process won't be able
to use more than 1GB?? (makes sense, but need a confirmation to justify
a kernel rebuild and reboot).
TIA for whatever help you can provide!
--
Judith Reed
jreed_at_appliedtheory.com
(315) 453-2912 x335
Received on Fri Nov 20 1998 - 14:06:16 NZDT