Re: [PATCH] speed up SATA

From: Jamie Lokier
Date: Mon Mar 29 2004 - 07:57:32 EST

Jens Axboe wrote:
> > Does it make sense to allow different numbers of outstanding TCQ-reads
> > and TCQ-writes?
> Might not be a silly thing to experiment with, definitely something that
> should be tested (added to list...)

Then there's another question: when deciding whether you can issue
another TCQ-read, do you compare the number of outstanding TCQ-reads
against the TCQ-read limit, or compare the _total_ number of
outstanding TCQs against the TCQ-read limit? Similarly for writes.

There are several other logical combinations that could be used.

Each condition will have a different effect on mean and peak latencies
under different load patterns. I'm not sure which makes more sense,
or even if multiple conditions should be used together.

-- Jamie
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