Subject: Re: ps vs /proc
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Brian C. Grayson <email@example.com>
Date: 02/23/2000 23:42:46
On Tue, Feb 22, 2000 at 01:37:40PM -0500, der Mouse wrote:
> I still think ps should be less stringent about what it demands of
> /proc before it's willing to give it the benefit of the doubt.
Look at the threads in tech-userlevel from March 1999, when I
first committed the ps /proc fallback. :)
I got the feeling at that time from the discussions that it was
better to give no information than possibly-erroneous
information. That's why ps (when using the /procfs fallback) does
an open, followed by verify_procfs_fd(), every time it examines a
file. Talk about paranoia!
<Snipped from your first note:>
% ps ax
ps: proc size mismatch (24192 total, 744 chunks).
ps: /proc exists but does not have a procfs mounted on it.
ps: fallback /proc-based lookup also failed. Giving up...
Hm. Line 223 of procfs_ops.c does a strcmp of the returned
f_fstypename against MOUNT_PROCFS (defined in
/usr/include/sys/mount.h), which is what failed. It might be
interesting, if you haven't already upgraded the whole system,
to have the warning print out what kind of filesystem it
_thinks_ it is. It'll probably just be "ocfs" or "fs"... :)