shmmax tops out at 2G?

Bill Moran wmoran at
Mon Dec 11 14:17:51 PST 2006

uname -a
FreeBSD db00.lab00 6.2-BETA3 FreeBSD 6.2-BETA3 #1: Fri Dec  8 09:27:37 EST 2006     root at db00.lab00:/usr/obj/usr/src/sys/DB-2850-amd64  amd64

sysctl kern.ipc.shmmax=2200000000
kern.ipc.shmmax: 2100000000 -> -2094967296

Looks like an unsigned 32-bit int.  That doesn't seem to scale as well as
would be expected on 64-bit arch.

Is this a mistake, or intentional?  I'm working with some big memory
systems, and I sure would like to allocate more than 2G for PostgreSQL
to use ...

Bill Moran
Collaborative Fusion Inc.

More information about the freebsd-questions mailing list