From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: libata .sg_tablesize: why always dividing by 2 ?
Date: Wed, 27 Feb 2008 10:16:17 +1100
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To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mark Lord <liml@rtr.ca>, Jeff Garzik <jgarzik@pobox.com>, Tejun Heo <htejun@gmail.com>, Alan Cox <alan@redhat.com>, IDE/ATA development list <linux-ide@vger.kernel.org>, FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>


> And the fact that this will totally blow fragmentation through the roof
> and cause half of the dma-map requests to fail on machines with small
> iommu has been totally ignored I suppose ?

Ok, so after checking those patches more closely, it appears that
alignment will only be enforced for devices that impose segment
boundaries, which means that normal devices can still pack. That
sounds good.

Ben.