From mboxrd@z Thu Jan  1 00:00:00 1970
From: Hans Reiser <reiser@namesys.com>
Subject: Re: I request inclusion of reiser4 in the mainline kernel
Date: Wed, 21 Sep 2005 14:16:50 -0700
Message-ID: <4331CDC2.1080300@namesys.com>
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To: Nikita Danilov <nikita@clusterfs.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>, Alan Cox <alan@lxorguk.ukuu.org.uk>, thenewme91@gmail.com, Christoph Hellwig <hch@infradead.org>, Denis Vlasenko <vda@ilport.com.ua>, chriswhite@gentoo.org, LKML <linux-kernel@vger.kernel.org>, ReiserFS List <reiserfs-list@namesys.com>, Nate Diller <ndiller@namesys.com>

Nikita Danilov wrote:

>Hans Reiser writes:
> > Horst von Brand wrote:
> > 
> > >
> > >
> > >Funny that the "texbook algorithms" aren't used in real life. Wonder why...
> > >  
> > >
> > Try BSD.  If the BSD book can be believed, they use"texbook algorithms".
>
>The "textbook" one-way elevator (as indeed exemplified by FreeBSD's
>src/sys/kern/subr_disk.c:bioq_disksort()) has well-known weaknesses. For
>example,
>
>    dd if=/dev/zero of=FILE
>
>can easily monopolize device queue and starve accesses to the blocks
>with low block numbers.
>
> > 
> > ;-)
>
>Nikita.
>
>
>  
>
Yes, and one can compensate for them  fairly cleanly.  I can't say more
without the customer releasing the code first.