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Re: [Xen-devel] Fwd: Re: struct page field arrangement

To: "Keir Fraser" <keir@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Fwd: Re: struct page field arrangement
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Thu, 01 Mar 2007 12:50:55 +0000
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>By the way, I think your proposed patch looks okay. However we already use
>page->index for foreign pages, in netback. Perhaps page->lru is also fair
>game? :-)

Not generally, there are arch-es that use it for their own purposes (look
back at the message from Hugh I originally forwarded). So even if none of
Xen's currently supported would use it (I didn't check), I wouldn't want to
introduce a lurking issue if anyone comes up with a new port.

I didn't check what private is being used for - while it can't be used for
PageForeign's destructor pointer, perhaps netback could use that one
rather than index? Or, even more likely, netback could use mapping if
PageForeign was switched over to index (while mapping overlays ptl, that
is benign to netback as it's not dealing with pte pages). But of course,
this requires thorough auditing of other uses of index.


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