topic Re: error cannot perform realloc in Operating System - HP-UX

error cannot perform realloc

billy_bunter — Sun, 06 Jun 2004 07:51:54 GMT

running a hp visualize B2000 workstation with 10.20 installed. Use it as a test station for tape drives over a SCSI bus. The system did quite happily run 6 drives now runs > 1 get the above error.
Cannot see anything obviouse

idea's thoughts appreciated

Re: error cannot perform realloc

doug hosking — Sun, 06 Jun 2004 23:32:20 GMT

What program is running when this happens?

My initial guess would be that you have run out of swap space or that the kernel tunable 'maxdsiz' is set too small. However this could also be something unrelated, such as an improper computation of how much memory to realloc.

Is there anything interesting in the output from /sbin/dmesg or in /var/adm/syslog/syslog.log?

Re: error cannot perform realloc

D Block 2 — Mon, 07 Jun 2004 07:21:23 GMT

realloc - sounds like a driver issue. have you searched itrc under patches for 10.20 ?

maybe there is an LVM patch - something to do with adding drives ?

Re: error cannot perform realloc

Bill Hassell — Mon, 07 Jun 2004 08:07:17 GMT

realloc is a system call to change extra memory allocation needed by a program. To prevent some programs from using all available memory, the kernel parameter maxdsiz limits the maximum amount allowed. Programs that exceed this limit will be signaled with an enomem (not enough memory available) error. Check the size of maxdsiz--the default is only 64megs, fairly small with some of today's programs. If your programs have not changed recently (config file, task sizes, etc) then look at swap space. If you're running more copies of the programs and you exceed RAM, swap space will be used and once out of swap space, the same error will occur.

Re: error cannot perform realloc

Ross Barton — Mon, 07 Jun 2004 16:00:25 GMT

Further to Bill's excellent email above - what has changed recently on your 10.20 box? Has someone done a patch upgrade etc.? Has someone removed/resized swap space? Has anyone played with Kernel configs? If this leads to naught, check for patches that you don't have and probably should - get them and install them.

Check these things before anything else. Bill is quite correcct about realloc running out a swap...

Re: error cannot perform realloc

Ross Barton — Mon, 07 Jun 2004 16:06:09 GMT

Further to my previous email. What's your swap space usage like? Has someone built a piece of code (perhaps that runs multiple processes) that has a memory leak and is eating up your swap space? Is the box paging much?

Use glance (the HP-UX Measureware suite) to check swap usage and examine what suspicious processes are doing.

For more info do a man on realloc - you'll find it's from the malloc(3C) group of C functions, part of the C standard library - and it might prompt you to think of other possible courses of action.