In article <34B6C099.F26186D3@msede.com> you write:
>[...]
>The man page specifies:
> If MAP_ANONYMOUS is set in flags:
> + A new memory region is created and initialized to all
> zeros.
> This memory region can be shared only with descendants
> of the current process.
> ...
Hmmm. This omits the case of
x = mmap(0, len, prot, MAP_ANON|MAP_SHARED, fd, offset)
with a valid file descriptor. That creates/attaches a shared memory
region that is identified by the file the file descriptor refers to,
but the file is not really used as backing storage (Effect of MAP_ANON).
Regards, Felix.