Message-ID: <40673950.4050703@pobox.com>
Date: Sun, 28 Mar 2004 15:45:04 -0500
From: Jeff Garzik <jgarzik@pobox.com>
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To: Andrew Morton <akpm@osdl.org>
CC: B.Zolnierkiewicz@elka.pw.edu.pl, axboe@suse.de, wli@holomorphy.com,
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Subject: Re: [PATCH] speed up SATA
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Andrew Morton wrote:
> Jeff Garzik <jgarzik@pobox.com> wrote:
> 
>> I like generic tunables such as "laptop mode" or "low latency" or "high 
>> throughput".  These sorts of tunables should affect the "automagic" 
>> calculations.
> 
> 
> Not sure.  Things like "low latency" and "high throughput" may need other
> things, such as "seek latency" and "bandwidth" as _inputs_, not as outputs.

I should probably better define the hypotheticals :)  I think of "laptop 
mode" or "low latency versus high throughput" more as high level binary 
flags, influencing widely varying things like from an ATA disk's "low 
noise versus high performance" tunable to the IO scheduler's deadlines.


> Such device parameters should have reasonable defaults, and use a userspace
> app which runs a quick seek latency and bandwidth test at mount-time,
> poking the results into sysfs.

Certainly...

	Jeff


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