Date: Fri, 30 Oct 1998 16:18:57 -0800 From: Mike Smith <mike@smith.net.au> To: David G Andersen <danderse@cs.utah.edu> Cc: hackers@FreeBSD.ORG, sclawson@cs.utah.edu, mike@fast.cs.utah.edu Subject: Re: nfs/amd hangs / getattr request flood problem Message-ID: <199810310018.QAA02943@dingo.cdrom.com> In-Reply-To: Your message of "Fri, 30 Oct 1998 15:37:02 MST." <199810302237.PAA01262@lal.cs.utah.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
> We're in the process of configuring some new machines (for personal and
> distributed build farm use), and we're seeing some atrocities with amd.
> The machines are running 3.0-RELEASE (plus the last few days of checked in
> fixes). They receive AMD maps via NIS and a static map, but disabling NIS
> doesn't affect things. We've made significant tweaks to the rest of the
> system configuration (disabling nis, mfs, slowing things down, etc) and
> tried it on multiple systems, and the problem keeps popping up. This
> behavior isn't exhibited in 2.2.x.
>
> We have AMD looking at /n/{machine}/path, with the actual mounts on
> /a/{machine}. When compiling with a source tree on /n/machine/path and an
> object tree on local /z, AMD can use up to 50% of the processor. Ktrace
> and tcpdump output shows that it's handling around 150 getattr requests
> per second, on "/n" and "/n/machine", and the ktrace indicates that that's
> the _only_ thing it's doing.
This may be related to a known defect in the BSD NFS code; we don't
cache getattr requests nor do we cache access requests.
> There don't seem to be any references to this in gnats or on the lists.
> We're working on forward-porting the 2.2.x amd to 3.0 to see if the
> behavior still exists, but in the meantime, if anyone has suggestions /
> thoughts / knows what's wrong and wants to clue me in, it'd be greatly
> appreciated. :)
2.2 has the same problems, although it's amd may not suffer the
consequences. You can save yourself a lot of effort by resurrecting
the 3.0 AMD from the attic (check out the relevant directories a few
days before the new AM-utils stuff went in).
--
\\ Sometimes you're ahead, \\ Mike Smith
\\ sometimes you're behind. \\ mike@smith.net.au
\\ The race is long, and in the \\ msmith@freebsd.org
\\ end it's only with yourself. \\ msmith@cdrom.com
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199810310018.QAA02943>