Shared memory info - how does one use struct shminfo?

[Guy Harris]

> /usr/include/sys/shm.h ends with an interesting structure, shminfo,
> which contains fields for various system config parameters related
> to System V shared memory. I've never seen a reference to how one
> should use this structure. Anybody know?

Yes.  You refer to it by opening "/dev/kmem", finding the address of the struct
named "shminfo" by looking through your kernel's namelist, and using that
address to find the right place in "/dev/kmem" to read.

In other words, there's no system call interface that gives it to you.