From: Andi Kleen <andi@firstfloor.org>
To: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>, Rik van Riel <riel@redhat.com>,
Andrew Vasquez <andrew.vasquez@qlogic.com>,
Christoph Hellwig <hch@infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] quiet down swiotlb warnings
Date: Sat, 2 Jun 2007 18:47:04 +0200 [thread overview]
Message-ID: <20070602164704.GQ7217@one.firstfloor.org> (raw)
In-Reply-To: <20070602152146.GE4342@rhun.haifa.ibm.com>
On Sat, Jun 02, 2007 at 06:21:46PM +0300, Muli Ben-Yehuda wrote:
> On Fri, Jun 01, 2007 at 10:26:01PM +0200, Andi Kleen wrote:
>
> > Normally swiotlb doesn't even try to bounce when dma mask is <=
> > end_pfn so something must be very wrong in your kernel. It
> > definitely isn't a mainline kernel. If this happens in Xen then Xen
> > just needs fixing -- it should not try to bounce when the normal
> > kernel wouldn't.
>
> Xen needs to bounce when the requested buffer is not contiguous in
> machine memory (and indeed uses swiotlb for that).
Then it should just restrict the sg list merging at the block layer
to never merge into anything larger than a page. Then this cannot
happen or only very rarely.
-Andi
next prev parent reply other threads:[~2007-06-02 16:47 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-01 17:30 [PATCH] quiet down swiotlb warnings Rik van Riel
2007-06-01 19:01 ` Andi Kleen
2007-06-01 18:12 ` Christoph Hellwig
2007-06-01 18:18 ` Rik van Riel
2007-06-01 19:37 ` Andi Kleen
2007-06-01 19:38 ` Rik van Riel
2007-06-01 19:47 ` Andi Kleen
2007-06-01 20:00 ` Andrew Vasquez
2007-06-01 20:14 ` Andi Kleen
2007-06-01 20:20 ` Rik van Riel
2007-06-01 20:26 ` Andi Kleen
2007-06-02 15:21 ` Muli Ben-Yehuda
2007-06-02 16:47 ` Andi Kleen [this message]
2007-06-01 19:57 ` Christoph Hellwig
2007-06-01 18:16 ` Andrew Vasquez
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