Date: Fri, 30 Nov 2001 12:47:29 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: Alexander Haderer <alexander.haderer@charite.de> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: FreeBSD performing worse than Linux? Message-ID: <200111302047.fAUKlT811090@apollo.backplane.com> References: <20011128153817.T61580@monorchid.lemis.com> <15364.38174.938500.946169@caddis.yogotech.com> <20011128104629.A43642@walton.maths.tcd.ie> <5.1.0.14.1.20011130181236.00a80160@postamt1.charite.de>
next in thread | previous in thread | raw e-mail | index | archive | help
Well, this is embarassing. I can reproduce this completely running
4.4-stable (Nov 17th kernel) on two machines.
With newreno turned on, a TCP NFS mount only gets 80K/sec. With newreno
turned off on the transmit side, a TCP NFS mount gets 7MB/sec. The
state of the delayed-ack sysctl is irrelevant. This is without running
any nfsiod's (which would mask the degredation of the synchronous
messaging).
I am tracking it down now.
-Matt
Matthew Dillon
<dillon@backplane.com>
:> (I wrote)
:> Hmm. I'll play with it a bit tomorrow. Er, later today. One thing
:> I noticed recently with NFS/TCP is that I have to run 'nfsiod -n 4'
:> on the client to get reasonable TCP performance. I don't think I
:> had to do that before. It sure sounds similar... like a delayed-ack
:> problem or improper transmit side backoff.
:>
:> It would be nice if someone able to reproduce the problem can test
:> the TCP connection with newreno turned off (net.inet.tcp.newreno)
:> and delayed acks turned off (net.inet.tcp.delayed_ack). If that
:> fixes the proble it narrows down our search considerably.
:
:Hello, I am the submitter of PR 32141 mentioned above,
:
:I did check it with a 4.3 Release server and 4.2 Release client using
:'mount_nfs -3 -T ...':
:setting net.inet.tcp.newreno=0 gives fast performance (about 8 Mbyte/s, same
:for udp mount), setting net.inet.tcp.newreno=1 gives 80kbyte/s.
:Setting net.inet.tcp.delayed_ack=0 has no influence (I checked all 4
:combinations).
:There is 'nfsiod -n 4' running at clientside (default setting if enabling
:nfs via sysinstall). We did not play around with nfsiod settings so far.
:
:Hope that helps
:
: Alexander
:
:------------------------------------------------------------------
:Alexander Haderer Charite
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?200111302047.fAUKlT811090>