From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <andi@firstfloor.org>
Subject: Re: Btrfs v0.16 released
Date: Thu, 14 Aug 2008 23:17:56 +0200
Message-ID: <20080814211756.GC13814@one.firstfloor.org>
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Cc: Andi Kleen <andi@firstfloor.org>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-btrfs <linux-btrfs@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>
To: Chris Mason <chris.mason@oracle.com>
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On Thu, Aug 14, 2008 at 05:00:56PM -0400, Chris Mason wrote:
> Btrfs defaults                  57.41 MB/s
> Btrfs dup no csum               74.59 MB/s 

With duplications checksums seem to be quite costly (CPU bound?)

> Btrfs no duplication            76.83 MB/s
> Btrfs no dup no csum no inline  76.85 MB/s

But without duplication they are basically free here at least
in IO rate. Seems odd?

Does it compute them twice in the duplication case perhaps?

-Andi