From: "H. Peter Anvin" <hpa@zytor.com>
To: Alex Elsayed <eternaleye@gmail.com>
Cc: linux-raid@vger.kernel.org, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 1/4] md: Factor out RAID6 algorithms into lib/
Date: Wed, 29 Jul 2009 11:16:49 -0700 [thread overview]
Message-ID: <4A709211.3080408@zytor.com> (raw)
In-Reply-To: <h3qhri$3di$2@ger.gmane.org>
>>
>> http://www.cs.utk.edu/~plank/plank/papers/CS-96-332.html even describes an
>> implementation _very_ similar to the current code, right down to using a
>> table for the logarithm and inverse logarithm calculations.
>>
We don't use a table for logarithm and inverse logarithm calculations.
Any time you do a table lookup you commit suicide from a performance
standpoint.
-hpa
next prev parent reply other threads:[~2009-07-29 18:16 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-13 14:11 [PATCH 1/4] md: Factor out RAID6 algorithms into lib/ David Woodhouse
2009-07-15 19:23 ` Dan Williams
2009-07-15 20:16 ` Chris Mason
2009-07-15 22:11 ` Dan Williams
2009-07-15 22:11 ` Dan Williams
2009-07-16 17:38 ` H. Peter Anvin
2009-07-17 14:22 ` Ric Wheeler
2009-07-17 15:20 ` H. Peter Anvin
2009-07-17 15:35 ` Ric Wheeler
2009-07-17 15:40 ` H. Peter Anvin
2009-07-17 15:47 ` Ric Wheeler
2009-07-17 15:49 ` H. Peter Anvin
2009-07-17 15:58 ` Ric Wheeler
2009-07-17 18:59 ` Alex Elsayed
2009-07-17 19:02 ` Alex Elsayed
2009-07-29 18:16 ` H. Peter Anvin [this message]
2009-07-17 19:12 ` Gregory Maxwell
2009-07-17 19:12 ` Gregory Maxwell
2009-07-18 11:53 ` David Woodhouse
2009-07-18 11:53 ` David Woodhouse
2009-07-18 12:45 ` H. Peter Anvin
2009-07-18 12:45 ` H. Peter Anvin
2009-07-18 18:50 ` Alex Elsayed
2009-07-18 18:52 ` Alex Elsayed
2009-07-29 18:20 ` H. Peter Anvin
2009-07-18 12:49 ` Ric Wheeler
2009-07-18 12:49 ` Ric Wheeler
2009-07-18 16:26 ` Dan Williams
2009-07-18 16:26 ` Dan Williams
2009-07-18 18:42 ` David Woodhouse
2009-07-18 20:04 ` Dan Williams
2009-07-19 18:04 ` David Woodhouse
2009-07-20 5:21 ` H. Peter Anvin
2009-07-17 15:51 ` H. Peter Anvin
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