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RE: [Xen-devel] can't create any more pv-on-hvm domains after~38under 3.

To: "Steve Ofsthun" <sofsthun@xxxxxxxxxxxxxxx>, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>
Subject: RE: [Xen-devel] can't create any more pv-on-hvm domains after~38under 3.3-testing
From: "James Harper" <james.harper@xxxxxxxxxxxxxxxx>
Date: Thu, 4 Dec 2008 11:28:38 +1100
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Thread-topic: [Xen-devel] can't create any more pv-on-hvm domains after~38under 3.3-testing
> We have been investigating a similar sounding bug (hung pages with
> elevated reference counts) that occur when blkback requests are issued
> over an iSCSI backend device.  The block requests appear to be running
> afoul of the lazy copy optimization added for netback.  In this path,
> foreign pages (assumed to be netback pages?) are manipulated specially
> the dma layer of the dom0 network stack.  On return to netback, the
> refs are cleaned up.

In my case it appears to be always a single page - if they were grants
on the ring then I would think I would be occasionally seeing zero or
multiple pages, so I think we might be chasing different issues.


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