Confused about create_proc_entry

[RuoMu Hu <huruomu@gmail.com>]

Hi!

I'm writing a kernel module to add a file under /proc/sys/kernel, but 
alway fail to create_proc_entry "sys/kernel/test".

I found that in proc_create() in fs/proc/generic.c (2.6.25.4):

/* At this point there must not be any '/' characters beyond *fn */
        if (strchr(fn, '/'))
                goto out;

So you cannot create_proc_entry with a name containing "/", but 
acturally create_proc_entry with "sysvipc/test" succeeds, and there are 
much other codes in the kernel that do this, e.g.:

fs/nfsd/nfsctl.c:        entry = create_proc_entry("fs/nfs/exports", 0, 
NULL);
fs/proc/proc_tty.c:    create_proc_read_entry("tty/ldiscs", 0, NULL, 
tty_ldiscs_read_proc, NULL);

I got pretty confused.  Any idea?  and is it possible to create a file 
in /proc/sys/kernel ? How?

Thanks!
Romu