topic SBRK value- in Operating System - HP-UX

SBRK value-

Yajuvendra Singh — Tue, 28 Mar 2006 03:18:51 GMT

Dear all,

I am trying to start a CAD application, but I am ending up with error stating;

current sbrk value = 0x404000 and increase to
Maximum sbrk value = 0x7A000000

How to increase the sbrk value, I am having HP-UX 11.11i c8000 Workstation.

Thanks in advance.

Regards
Yajuvendra Singh

Re: SBRK value-

Muthukumar_5 — Tue, 28 Mar 2006 03:24:51 GMT

You have to tune maxdsiz and maxdsiz_64bit kernel tunable parameters.

# kmtune -q maxdsiz_64bit
# kmtune -q maxdsiz

will give available data. You have to tune with kmtune or sam.

http://docs.hp.com/en/B3921-90010/maxdsiz.5.html

Read that page.

--
Muthu

Re: SBRK value-

Ninad_1 — Tue, 28 Mar 2006 04:15:08 GMT

Hi,

The sbrk value relates to size of data segment available to a process.

http://www.scit.wlv.ac.uk/cgi-bin/mansec?2+sbrk

You can check the current kernel parameter as mentioned above and for your session by ulimit -a ( The data field will show you your currrent size - I guess it is currently 64 KB)

You can change the maxdsiz or maxdsiz_64 bit depending whether the program you are using is 32-bit or 64-bit respectively.
You can change through SAM which is the easiest and safest method.
Also I guess the maxdsiz kernel parameter can be dynamically changed (no reboot required) for HP-UX 11.11.

Hope this helps,
Ninad

Re: SBRK value-

Don Morris_1 — Tue, 28 Mar 2006 10:28:51 GMT

No, maxtsiz is dynamic in 11.11 - maxdsiz (and maxssiz) became dynamic in 11.22 and subsequent releases. For 11.11, you'll still have to reboot to have changes to maxdsiz take effect.