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Date: Tue, 9 Oct 2012 21:21:12 -0400
From: Garrett Wollman <wollman@bimajority.org>
To: Rick Macklem <rmacklem@uoguelph.ca>
Subject: Re: NFS server bottlenecks
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<<On Tue, 9 Oct 2012 20:18:00 -0400 (EDT), Rick Macklem <rmacklem@uoguelph.ca> said:

> And, although this experiment seems useful for testing patches that try
> and reduce DRC CPU overheads, most "real" NFS servers will be doing disk
> I/O.

We don't always have control over what the user does.  I think the
worst-case for my users involves a third-party program (that they're
not willing to modify) that does line-buffered writes in append mode.
This uses nearly all of the CPU on per-RPC overhead (each write is
three RPCs: GETATTR, WRITE, COMMIT).

-GAWollman