> >   The problem with binary format is, if the kernel changes, bang!
> > ps/top/systat/xosview are useless until you can upgrade userland.
> 
> That's not true. While this is a problem, it is not a problem with
> binary format itself.

I think so, too.

> The real problem is, whether you have a 1:1 kernel->userspace data
> structure mapping without some extra version/tag/whatever information.

This is also true.

But in the ps/top/systat/xosview case, is this really needed ?
If there is a interface which provides the exact information needed 
by ps/top/systat/xosview, the problem will disappear.

The real problem is "struct kinfo_proc" includes "struct proc" as it
is. I think this is the source of the problem. While this is the
kernel/userland interface, the format of "struct kinfo_proc" should
be independent of kernel version, and sysctl(2) for "struct kinfo proc"
should convert "struct proc" to version independent format.
Shouldn't it ?
--
soda