From: Steve Wise <swise@opengridcomputing.com>
To: benh@au1.ibm.com
Cc: Roland Dreier <rdreier@cisco.com>,
linux-kernel@vger.kernel.org,
OpenFabrics General <general@lists.openfabrics.org>,
Benjamin Herrenschmidt <bherren@au1.ibm.com>,
Wen Xiong <wenxiong@us.ibm.com>, Olof Johansson <olof@lixom.net>,
Paul Mackerras <pmac@au1.ibm.com>
Subject: Re: iommu dma mapping alignment requirements
Date: Thu, 20 Dec 2007 15:02:06 -0600 [thread overview]
Message-ID: <476AD84E.4000507@opengridcomputing.com> (raw)
In-Reply-To: <1198181862.6779.3.camel@pasglop>
Benjamin Herrenschmidt wrote:
> Adding A few more people to the discussion. You may well be right and we
> would have to provide the same alignment, though that sucks a bit as one
> of the reason we switched to 4K for the IOMMU is that the iommu space
> available on pSeries is very small and we were running out of it with
> 64K pages and lots of networking activity.
>
But smarter NIC drivers can resolve this too, I think, but perhaps
carving up full pages of mapped buffers instead of just assuming mapping
is free...
perhaps...
next prev parent reply other threads:[~2007-12-20 21:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-20 17:14 iommu dma mapping alignment requirements Steve Wise
2007-12-20 17:29 ` [ofa-general] " Tom Tucker
2007-12-20 18:07 ` Roland Dreier
2007-12-20 19:11 ` Steve Wise
2007-12-20 19:29 ` Steve Wise
2007-12-20 20:21 ` Benjamin Herrenschmidt
2007-12-20 21:22 ` Steve Wise
2007-12-20 20:17 ` Benjamin Herrenschmidt
2007-12-20 21:02 ` Steve Wise [this message]
2007-12-20 21:26 ` Benjamin Herrenschmidt
2007-12-20 22:12 ` Steve Wise
2007-12-20 23:49 ` Benjamin Herrenschmidt
2007-12-21 4:49 ` Steve Wise
2007-12-21 5:38 ` Benjamin Herrenschmidt
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