From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH RFC 00/10] Xen balloon page compaction
	support
Date: Wed, 15 Oct 2014 17:54:24 +0100
Message-ID: <543EA6C0.20903@citrix.com>
References: <1413388459-4663-1-git-send-email-wei.liu2@citrix.com>
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To: Wei Liu <wei.liu2@citrix.com>, xen-devel@lists.xen.org
Cc: boris.ostrovsky@oracle.com, david.vrabel@citrix.com, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com
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On 15/10/14 16:54, Wei Liu wrote:
> Hi all
>
> This is a prototype to make Xen balloon driver work with balloon page
> compaction. The goal is to reduce guest physical address space fragmentation
> introduced by balloon pages. Having guest physical address space as contiguous
> as possible is generally useful (because guest can have higher order pages), and
> it should also help improve HVM performance (provided that guest kernel knows
> how to use huge pages -- Linux has hugetlbfs and transparent huge page).

After you have defragmented guest physical memory, does Linux use
2MB/1GB superpages more readily?

On what basis do you think this will improve HVM performance?  The HAP
tables still remain fragmented after ballooning.

~Andrew