From: "Andrew Theurer" Subject: Re: [NFS] Re: [PATCH] zerocopy NFS for 2.5.36 Date: Wed, 16 Oct 2002 21:03:33 -0500 Sender: linux-kernel-owner@vger.kernel.org Message-ID: <012d01c27581$677d2180$2a060e09@beavis> References: <15786.23306.84580.323313@notabene.cse.unsw.edu.au><20021014.210144.74732842.taka@valinux.co.jp><15788.57476.858253.961941@notabene.cse.unsw.edu.au> <20021015.213102.80213000.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Cc: , , Return-path: To: , "David S. Miller" List-ID: > From: Neil Brown > Date: Wed, 16 Oct 2002 13:44:04 +1000 > > Presumably on a sufficiently large SMP machine that this became an > issue, there would be multiple NICs. Maybe it would make sense to > have one udp socket for each NIC. Would that make sense? or work? > It feels to me to be cleaner than one for each CPU. > > Doesn't make much sense. > > Usually we are talking via one IP address, and thus over > one device. It could be using multiple NICs via BONDING, > but that would be transparent to anything at the socket > level. > > Really, I think there is real value to making the socket > per-cpu even on a 2 or 4 way system. I am still seeing some sort of problem on an 8 way (hyperthreaded 8 logical/4 physical) on UDP with these patches. I cannot get more than 2 NFSd threads in a run state at one time. TCP usually has 8 or more. The test involves 40 100Mbit clients reading a 200 MB file on one server (4 acenic adapters) in cache. I am fighting some other issues at the moment (acpi wierdness), but so far before the patches, 82 MB/sec for NFSv2,UDP and 138 MB/sec for NFSv2,TCP. With the patches, 115 MB/sec for NFSv2,UDP and 181 MB/sec for NFSv2,TCP. One CPU is maxed due to acpi int storm, so I think the results will get better. I'm not sure what other lock or contention point this is hitting on UDP. If there is anything I can do to help, please let me know, thanks. Andrew Theurer