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From: Oliver Neukum <Oliver.Neukum@lrz.uni-muenchen.de>
To: Richard Gooch <rgooch@ras.ucalgary.ca>,
        Daniel Phillips <phillips@bonn-fries.net>
Subject: Re: [resent PATCH] Re: very slow parallel read performance
Date: Mon, 27 Aug 2001 22:09:25 +0200
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Am Montag, 27. August 2001 21:55 schrieb Richard Gooch:
> Daniel Phillips writes:
> > The quesion is, how do you know you're streaming?  Some files are
> > read/written many times and some files are accessed randomly.  I'm
> > trying to avoid penalizing these admittedly rarer, but still
> > important cases.
>
> I wonder if we're trying to do the impossible: an algorithm that works
> great for very different workloads, without hints from the process.

For streaming we should be able to detect consecutive reads.
If it's not that easy could we not measure hit/miss ratios ?

> Shouldn't we encourage use of madvise(2) more? And if needed, add
> O_DROPBEHIND and similar flags for open(2).

For symmetry rather fadvise. Besides usage patterns may change.

	Regards
		Oliver