From: Keir Fraser <keir.fraser@eu.citrix.com>
To: "Y. D." <duyuyang@gmail.com>, xen-devel <xen-devel@lists.xensource.com>
Subject: Re: Different: nr_pages vs. max_pfn
Date: Wed, 19 Nov 2008 09:54:27 +0000 [thread overview]
Message-ID: <C54992D3.1F600%keir.fraser@eu.citrix.com> (raw)
In-Reply-To: <200811191745479618049@gmail.com>
The shared_info value is set up by the guest itself during boot. It's larger
because Linux adds extra space at the end of its p2m map for backend
drivers.
-- Keir
On 19/11/08 09:45, "Y. D." <duyuyang@gmail.com> wrote:
> Hi,
>
> In start_info, there is a field nr_pages definig how much memory is allocated
> to the domain, which is obvious.
> While in shared_info, there is a field max_pfn. I don't know why max_pfn is
> not equal to nr_pages.
> Say for 32MB memory, nr_pages = 8192, while max_pfn = 10240 (may vary?), of
> which 2048 pfn's have invalid mfn.
> Can anybody explain that why max_pfn is larger? Is it static or dynamic?
> Furture, does pfn to mfn frame mapping ever change? Hopefully not.
>
> Thanks,
> Shawn
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
next prev parent reply other threads:[~2008-11-19 9:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-19 9:45 Different: nr_pages vs. max_pfn Y. D.
2008-11-19 9:54 ` Keir Fraser [this message]
2008-11-19 10:23 ` Jayaraman, Bhaskar
2008-11-19 12:22 ` Y. D.
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