Max continuous shared memory

[expirexp]

Hi all,

I am new to here, hope can get your help~

How can I find the followings in HP-UX
1. max continuous shared memory (global)
2. max continuous shared memory (private)
3. total memory (global)
4. total memory (private)
5. total free memory (global)
6. total free memory (private)

Thanks a lot!

#uname -a
HP-UX ux08kw B.11.00 U 9000/800 130474675 unlimited-user license

[Arunvijai_4 · Accepted solution]

Hi,

You should take a look at this paper,

ftp://eh:spear9@hprc.external.hp.com/memory.htm


-Arun

[expirexp]

Thanks. The page is very useful.

BTW,

1. I use #shminfo -g | grep FREE to get the FREE global memory, is total free global memory = sum of them?

2. i use #shminfo -p
Shared space from Window id 1 (q3private):
Space Start End Kbytes Usage
Q2 0xffffffff.0x40000000-0x7fffffff 1048576 OTHER
Q3 0xffffffff.0x80000000-0xbfffffff 1048576 OTHER

is total free private memory = 1048576+1048576=2GB?

FYI: my sysem has physical ram 2GB.

Thanks all

[Arunvijai_4]

1. I use #shminfo -g | grep FREE to get the FREE global memory, is total free global memory = sum of them?

It will show free global memory.

2. i use #shminfo -p
Shared space from Window id 1 (q3private):
Space Start End Kbytes Usage
Q2 0xffffffff.0x40000000-0x7fffffff 1048576 OTHER
Q3 0xffffffff.0x80000000-0xbfffffff 1048576 OTHER

is total free private memory = 1048576+1048576=2GB?

FYI: my sysem has physical ram 2GB.

Nope, I think it is 1GB only.

-Arun

[ASOEASTGEOGRAPHY]

The tool you need is shminfo. Download a copy from:

ftp://contrib:9unsupp8@hprc.external.hp.com/sysadmin/programs/shminfo

Your biggest challenge using large shared memory segments will be for 32bit programs. There is only one default map for shared memory and when programs (that use shared memory) crash or are killed with -9, the segments remain and cannot be reused, leading to memory fragmentation. Even so, the largest segment is about 900 megs (or up to 2750 megs for a SHARED_MAGIC program).

To avoid the limitations for 32bit shared memory fragmentation, change the programs to 64bits, or look at Memory Windows.