From owner-freebsd-hackers  Fri Jun 22 17:26:11 2001
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Date: Fri, 22 Jun 2001 17:24:49 -0700 (PDT)
From: Richard Hodges <rh@matriplex.com>
To: Josh Osborne <stripes@mac.com>
Cc: freebsd-hackers@FreeBSD.ORG
Subject: Re: question: aio / nbio / kqueue
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On Fri, 22 Jun 2001, Josh Osborne wrote:

> On Friday, June 22, 2001, at 07:01  PM, E.B. Dreger wrote:
> > My question is, from a performance standpoint, in what situations are
> > these techniques most appropriate?
 
> AIO is good when you are not receiving much data (or not receiving
> it very frequently), and presumably want very low latency.

What if you want good performance with "moderate" disk IO, say ten
to twenty megabytes per second continuously?

I tried AIO some months ago (4.1R or 4.2R), but had some trouble
with AIO, mainly that it seemed to lose track of half my files.
Not any particular files, it seemed that at any moment it would
just pick ten or so (out of maybe 20-25 files) to ignore at any
given time.

Is there any better solution than just forking off a process for
each file and letting the kernel handle the details?

Thanks,

-Richard

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   Richard Hodges   | Matriplex, inc.
   Product Manager  | 769 Basque Way
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