From: Greg Banks <gnb@melbourne.sgi.com>
Subject: Re: Different NFSSVC_MAXBLKSIZE for udp and tcp clients?
Date: Thu, 27 Nov 2003 11:21:07 +1100
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To: Neil Brown <neilb@cse.unsw.edu.au>
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Neil Brown wrote:
> 
> request size is completely under the control of the client via rsize
> and wsize (except that you cannot exceed the server's maximum).

The point is that the server's maximum is too low, at least when
the client and server are powerful machines with a clean network
between them (i.e. a significant part of SGI's customers).

When I say too low, I have two separate issues:

1.  wsize<16K means an Altix client does synchronous writes, which
    results in a catastrophic performance hit (writes proceed at
    no more than 0.7% of line rate on gige).  This is a hot issue
    right now.

2.  Experience with IRIX shows that (up to a point) better performance
    can be achieved for some loads with larger transfer sizes.  On
    IRIX that point is beyond Linux' current hardcoded maximums.  This
    is more of a long-term issue.

Greg.
-- 
Greg Banks, R&D Software Engineer, SGI Australian Software Group.
I don't speak for SGI.


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