Manfred Spraul wrote:
> 
> Mark Swanson wrote:
> >
> > Hello,
> >
> > ipcs (msg) gives incorrect results if used-bytes is above 65536. It
> > stays at 65536 even though messages are being read and removed from the
> > msg queue.
> >

Ok, does the value stay at 65536 or 65535?
It should stay at 65535 if you use a too old version of util-linux.

Please upgrade (see linux/Documentation/Changes)

The proc interface at /proc/sysvipc/msg should report the correct
numbers.

If you want to access values > 65535 from your app you have 2 options:

1) use the new msqid64_ds structure. You must pass IPC_64 to the msgctl
call. This is the only option if you need correct 32-bit uids.
Check the util-linux source, I don't have sample code.
msqid64_ds is only supported by the 2.4 kernel.

2) the old msqid_ds structure also support 32-bit queue length, an
unused field was reused. No support for 32-bit uids.

#define msg_lqbytes	__rwait;

I've attached my old sample code.
--
	Manfred