topic Re: Process specific memory utilization in Operating System - OpenVMS

Process specific memory utilization

roose — Mon, 10 Apr 2006 20:46:44 GMT

Hi Folks,

Most of the time, I am asked by some of my users to provide some statistics on some processes. I usually use Polycenter Performance Advisor in generating CPU and memory statistics, but we do have T4 installed on our systems as well. Process CPU utilization is easy to obtain using PSPA, but I always have doubt if I am giving the correct data for process memory utilization, as I know that getting this is not straight-forward. For now, I usually give them the average working set size.

I have attached a sample output from a PSPA command containing data from the following command:

advise perf report perf-
/begin=7-mar-2006 -
/end=8-mar-2006 -
/inter=3600 -
/process = (focus=mem,primary=process) -
/node=s1a01 -
/include=(noall,process,summa) -
/out=test.rpt

If I am to get the average memory utilization of a process, which column/s should I use? Or is there a much better PSPA command to get what I would like to obtain?

Can this be done using T4? If so, what T4 category/parameters should I look at?

By the way, I am getting my data from a 2-node clustered ES80/OVMS v7.3-1.

Thanks in advance for your help!

Re: Process specific memory utilization

Volker Halle — Tue, 11 Apr 2006 01:38:13 GMT

Roose,

the PSPA data is all you need:

Ave WSsize = Ave Private + Ave Global

This is the real no. of process private and global pages in the working set list.

Ave WSlist is the Average Working Set LIMIT (i.e. PHD$L_WSSIZE = the max. no. of working set entries a process is allowed to use at any time, but not necessarily using).

The physical memory utilization of a process is the average number of private pages plus some percentage of the average number of global pages used by this process. As global pages can be used by multiple processes at the same time, it's hard - if not impossible - to tell the average usage of global physical pages by a process.

The true average no. of physical pages used by a process is some value less than the sum of private and global pages, but larger than the private pages.

As T4 does not report data for all processes by default, you can't really obtain this data from T4, except for those processes, which are included in the /Process_Name=(...) selection list. The T4 data would be [MON.PROC]*process* PagesGbl and PagesProc

Volker.

Re: Process specific memory utilization

roose — Tue, 11 Apr 2006 20:08:51 GMT

Thanks Volker for your input! I am closing this thread as the specific question that I have asked has been answered.