Shared memory

From: Horsnell T. <tsh_at_mrc-lmb.cam.ac.uk>
Date: Tue, 19 Sep 2000 10:17:11 +0100 (BST)

I'm having problems using the shared-mem tools shmget shmat etc.

I want to be able to declare a C or Fortran array, and map this into
a shared-mem area with shmat, but always get the ENOMEM error
(not enough data space available to attach the shared mem region)

The shmat works if I choose zero as the virtual address for attachment,
but not if I specify the address of the C/Fortran array.

Looks like I'm misunderstanding something here - I cant find any more
more docs other than the man pages. Are there any?

Also, from observation, it seems as if the shared mem area stays put
in physical memory until it gets deleted with a

shmctl(shmid, IPC_RMID, &shmidds)

and so it would seem possible for a user to consume memory beyond
'limit' limits by creating many shmem areas.
Are there any tools to monitor what is going on with shared-mem areas?
Again I couldnt find anyting so far.

Cheers,
Terry.



Terry Horsnell (tsh_at_mrc-lmb.cam.ac.uk)
Computer Manager
Medical Research Council
Lab of Molecular Biology
Hills Road
CAMBRIDGE CB2 2QH
U.K.
Phone: +44 (0)1223 248011
Fax: +44 (0)1223 213556
Received on Tue Sep 19 2000 - 09:18:42 NZST

This archive was generated by hypermail 2.4.0 : Wed Nov 08 2023 - 11:53:41 NZDT