Messages in this thread | | | Date | Wed, 14 Feb 2001 15:53:02 -0500 (EST) | From | "Gord R. Lamb" <> | Subject | Re: Samba performance / zero-copy network I/O |
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On Wed, 14 Feb 2001, Jeremy Jackson wrote:
> "Gord R. Lamb" wrote: > > > Hi everyone, > > > > I'm trying to optimize a box for samba file serving (just contiguous block > > I/O for the moment), and I've now got both CPUs maxxed out with system > > load. > > > > (For background info, the system is a 2x933 Intel, 1gb system memory, > > 133mhz FSB, 1gbit 64bit/66mhz FC card, 2x 1gbit 64/66 etherexpress boards > > in etherchannel bond, running linux-2.4.1+smptimers+zero-copy+lowlatency) > > > > CPU states typically look something like this: > > > > CPU states: 3.6% user, 94.5% system, 0.0% nice, 1.9% idle > > > > .. with the 3 smbd processes each drawing around 50-75% (according to > > top). > > > > When reading the profiler results, the largest consuming kernel (calls?) > > are file_read_actor and csum_partial_copy_generic, by a longshot (about > > 70% and 20% respectively). > > > > Presumably, the csum_partial_copy_generic should be eliminated (or at > > least reduced) by David Miller's zerocopy patch, right? Or am I > > misunderstanding this completely? :) > > I only know enough to be dangerous here, but I believe you will need to > be using one of the network cards whose driver actually uses the > zero-copy patches, and/or which can perform tcp checksum in hardware > (of the network card).
Hmm. Yeah, I think that may be one of the problems (Intel's card isn't supported afaik; if I have to I'll switch to 3com, or hopelessly try to implement support). I'm looking for a patch to implement sendfile in Samba, as Alan suggested. That seems like a good first step.
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