topic Re: ps -elf SZ column in Operating System - HP-UX

ps -elf SZ column

james p. boyle — Fri, 16 Apr 2004 08:09:44 GMT

HPUX 11.11
ps -elf list a SZ value that is described as "The size of blocks of the core image of the process."

How big is a block in bytes?
If I know the answer, can I summ all the process blocks plus the free pages from vmstat and get my total 2GB of memory or something close for that instant in time?

Re: ps -elf SZ column

Jeff Schussele — Fri, 16 Apr 2004 08:11:27 GMT

Hi James,

4KB is the block size

Rgds,
Jeff

Re: ps -elf SZ column

Navin Bhat_2 — Mon, 19 Apr 2004 11:21:54 GMT

4096 bytes (4k) is the default block size unless you have chosen to change the kernel.

SZ is a UNIX95 standard part of ps.

The size in physical pages of the core image of the process, including text, data, and stack space.

No you cannot summ all these blocks mainly because these do not account for shared memory, memory mapped files etc.

Again if you could be more specific what you want to achieve it would be easier to suggest an approach for you.

Re: ps -elf SZ column

A. Clay Stephenson — Mon, 19 Apr 2004 11:32:25 GMT

You would be better advised to assert the XPG4 ps behavior by setting the UNIX95 env. variable.

e.g.
UNIX95= ps -e -o vsz,pid,comm

vsz will always be in KB.

Memory calculations are extremely difficult because shared library code might be used by many processes. The same is true of shared memory segments.

Re: ps -elf SZ column

Navin Bhat_2 — Mon, 19 Apr 2004 13:28:12 GMT

Couple of clarifications there 1st I presume that you meant page size not block size. Either way the default pages are 4k in size.

You can use sz,vsz after setting the UNIX95 variable to the open portability standard.

export UNIX95=XPG4

Again "sz" is the real and "vsz" is the virtual size of the core image (data,text and stack) this does not include memory mapped or shared memory regions and cannot be used to sum physical memory totals with vmstat free pages.

Use top/glance as a good starting tool to get per process memory layout information.