topic Re: kernel tunable parameter file in Operating System - HP-UX

kernel tunable parameter maxrsessiz exceeded

Billa-User — Wed, 16 Mar 2011 07:42:55 GMT

hello,
we have big problems at a HPUX 11.31 server with a ORACLE application ( ORACLE application server).

When we stopped the process(es), we got following error:

Pid 18791 received a SIGSEGV for stack growth failure.
Possible causes: insufficient memory or swap space,
or stack size exceeded maxrsessiz
or stack size limit is set too small.

i have never heard before of kernel tunable parameter maxrsessiz/maxrsessiz_64bit.

actual we have the default values ( in attachment).

what should be the new value of maxrsessiz ?
how can i see the actual maxrsessiz value of a process (PID) ?

description of maxrsessiz :

maxrsessiz(5) -- maximum size (in bytes) of the RSE

Itanium-based systems utilize a per-process register stack in main memory (for more information see the Intel IA-64 Architecture Software Developer's Manual, Volume 2, Chapter 6). This stack moves registers between the physical registers and main memory and is maintained by the Register Stack Engine (RSE). maxrsessiz determines the size of this stack. Who is Expected to Change This Tunable?

Re: kernel tunable parameter maxrsessiz exceeded

Bill Hassell — Wed, 16 Mar 2011 10:26:29 GMT

Since this is not some locally written program with unusual features (very large stack sizes are often bad programming style), I would look at swapinfo -tam. While you may have plenty of RAM, over a period of time, your system may have deactivated many idle programs and rolled them out to swap. If they remain idle, there is nothing to bring them back and eventually swap space can be exhausted.

Re: kernel tunable parameter maxrsessiz exceeded

Bill Hassell — Wed, 16 Mar 2011 10:26:30 GMT

Re: kernel tunable parameter maxrsessiz exceeded

Billa-User — Wed, 16 Mar 2011 11:41:01 GMT

we also think about a problem of threads ?

we increase max_thread_proc , old percentage was about 50 % ?

we embedding know how from the LINUX department.

what is the similar command on HP-UX ?

LINUX: Get info about threads

Type the following command:
# ps -eLf
# ps axms

regards

Re: kernel tunable parameter maxrsessiz exceeded

Uday_S_Ankolekar — Wed, 16 Mar 2011 16:33:10 GMT

try kcusage command

Re: kernel tunable parameter maxrsessiz exceeded

Steven E. Protter — Wed, 16 Mar 2011 17:28:35 GMT

Shalom,

kcalarm can help you set up email based alarms.

You can set the percentage of total parameter being set as an alarm point to allow yourself to be proactive.

man kcalarm

SEP

Re: kernel tunable parameter maxrsessiz exceeded

Dennis Handly — Wed, 16 Mar 2011 17:59:06 GMT

>Pid 18791 received a SIGSEGV for stack growth failure.
>or stack size exceeded maxrsessiz
>I have never heard before of kernel tunable parameter maxrsessiz

Hmm, I didn't know that maxrsessiz was specific to the message. In most cases 8 Mb is good enough for the RSE stack. I've only seen a few cases where you have so much recursion that you need to increase the stack to 16 Mb. And two of them were in the aCC6 compiler.

>what should be the new value of maxrsessiz?
>how can I see the actual maxrsessiz value of a process?

Try 16 Mb. To see the actual value, it would help if you have a core file. Or be able to debug it with gdb.
But the actual value would be maxrsessiz of course. :-)
Or did you want to see the current RSE stack usage of a PID that hasn't aborted yet?

>we also think about a problem of threads?

No, with threads you will probably just get a signal 11 when it hits the guard page. But there is a RSE stack for threads that is typically trivial in size, compared to 8 Mb.

Re: kernel tunable parameter file

henrymanda — Mon, 01 Aug 2011 06:16:30 GMT

Hi,

I need to extract all the kernel tunables in a text file. Which file contains the list of all the tunables and their assigned values?

Kindly assist.

Re: kernel tunable parameter file

Hiren N Dave — Mon, 01 Aug 2011 08:02:13 GMT

#kctune > filename

#kcmodule > filename