kern/144330: [nfs] mbuf leakage in nfsd with zfs

[Rick Macklem]

The following reply was made to PR kern/144330; it has been noted by GNATS.

From: Rick Macklem <rmacklem at uoguelph.ca>
To: Kai Kockro <kkockro at web.de>
Cc: Daniel Braniss <danny at cs.huji.ac.il>,
        Mikolaj Golub <to.my.trociny at gmail.com>,
        Jeremy Chadwick <freebsd at jdc.parodius.com>, freebsd-fs at freebsd.org,
        bug-followup at freebsd.org, gerrit at pmp.uni-hannover.de
Subject: Re: kern/144330: [nfs] mbuf leakage in nfsd with zfs
Date: Wed, 24 Mar 2010 21:04:53 -0400 (EDT)

 On Wed, 24 Mar 2010, Kai Kockro wrote:
 
 > Hi,
 >
 > after 3 days with the first patch ( FreeBSD 8-STABLE AMD64, old nfsd ):
 >
 > netstat -m
 > 5732/10528/16260 mbufs in use (current/cache/total)
 > 4825/10131/14956/262144 mbuf clusters in use (current/cache/total/max)
 >
 > It looks very fine. I'll patch with the final corrections and then test again.
 >
 
 Sounds good. Thanks for letting us know.
 
 > But why i have the same issues? I dont use UDP connects, only TCP?!
 >
 Hmm, from what I can see, the replay cache is used for both UDP and
 TCP in the regular NFS server. If I'm correct on that, any retry of
 an RPC over TCP could cause the leak. (Retries of an RPC over TCP
 are infrequent, with the likelyhood differing between clients. I
 can only guess that your TCP clients do retries?)
 
 rick