free up memory

[Eileen Millen]

Does anyone know if there is a way to free up memory without rebooting? The system has been up for 2 months running Scientific codes. There is a job on it that has to run for about another week. A job that ran last week cannot run now. It complains about memory. Our maxdsiz, maxtsiz and maxssiz are 805306368, 67108864 and 75497472.
swapinfo shows 440Mb free
# swapinfo
Kb Kb Kb PCT START/ Kb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 524288 26048 498240 5% 0 - 1 /dev/vg00/lvol2
reserve - 265824 -265824
memory 833752 393288 440464 47%

dmesg info
Memory Information:
physical page size = 4096 bytes, logical page size = 4096 bytes
Physical: 1179648 Kbytes, lockable: 830608 Kbytes, available: 955456 Kbytes

[Rick Garland]

ipcs may be what you are looking for. With the ipcs command, you can see what process/app has got a memory block and in using the ipcrm command you can remove it.

Doing a SEARCH on ipcrm will yield additional posts related to this subject as well.

[John Palmer]

Eileen,

It may indeed be that your problems are due to shared memory as Rick suspects. If 'ipcs -ma' indicates that this is the case then one possible solution (providing that you are on HP-UX 11) is 'Memory Windows'. Check out the white paper which is in /usr/share.doc/mem_wndows.txt.

Regards,
John

[James R. Ferguson · Accepted solution]

Eileen:

I have an application for which we do this somewhat routinely -- at least at one time it seemed to be necessary. Essentially, I do the following:

# ipcs -mo # show shared memory & active message queue information

If the seventh ($7), NATTCH, field returned = 0 then there are no active processes associated with this shared memory segment, so capture the memory ID ($2) to use next.

# icprm -m $MEMID

...JRF...

[Eileen Millen]

Thanks for your answers.
There was one process with 0 in the NATTCH field. I got rid of the process with ipcrm.
The forums are an excellent resource.