Subject: Re: increasing share memory
To: Perry E. Metzger <>
From: Matthias Buelow <>
List: netbsd-users
Date: 03/04/2002 01:34:06
Perry E. Metzger writes:

>In fact, the number in question only gives a maximum to the size of
>the sysv shared memory -- since the shared memory is pageable and
>handled by the same mechanisms as mmapped shared memory etc. the limit
>is really an artifact of the past and should be eliminated.

Hmm, couldn't the relevant system calls simply be replaced with
library functions using the (imho) a bit more appropriate mmap()
style shared memory functions? mmapping MAP_ANON|MAP_SHARED
(4.3+BSD) or MAP_SHARED with /dev/zero (SVr4) are more modern
methods for shared memory acquisition, and both work on NetBSD.
They also don't suffer the kernel limits as System-V IPC (<4.0)
shm segments do...