From: Dave McCracken <dcm@mccr.org>
To: Keir Fraser <keir.fraser@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
Xen Developers List <xen-devel@lists.xensource.com>
Subject: Re: Re: [PATCH] Add hypercall to mark superpages to improve performance
Date: Sun, 2 May 2010 20:55:32 -0500 [thread overview]
Message-ID: <201005022055.32509.dcm@mccr.org> (raw)
In-Reply-To: <C80360DB.11A0B%keir.fraser@eu.citrix.com>
On Sunday 02 May 2010, Keir Fraser wrote:
> Oh, now I think about it, although your suggestion deals with type
> conflicts, it doesn't handle page lifetimes. What if a page is only mapped
> as a superpage? The page->count_info would not be incremented by the
> superpage mappings, and the page would be erroneously freed to the Xen free
> pools? So I'm not so sure we can so easily avoid the
> mess-with-every-page's-refcount on first mapping of a superpage... :-(
It should be simple enough to also check superpage->count_info in those
places. So the total mappings of a page would be page->count_info +
superpage->count_info. Good thing you suggested we also have a count in the
superpage_info struct :)
Dave
next prev parent reply other threads:[~2010-05-03 1:55 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-28 14:33 [PATCH] Add hypercall to mark superpages to improve performance Dave McCracken
2010-04-28 6:58 ` Keir Fraser
2010-04-30 19:43 ` Dave McCracken
2010-04-30 21:30 ` Keir Fraser
2010-04-30 22:10 ` Keir Fraser
2010-04-30 21:34 ` Keir Fraser
2010-04-30 21:43 ` Dave McCracken
2010-04-30 22:03 ` Keir Fraser
2010-05-02 21:34 ` Dave McCracken
2010-05-02 23:54 ` Keir Fraser
2010-05-03 0:03 ` Keir Fraser
2010-05-03 1:55 ` Dave McCracken [this message]
2010-05-03 16:09 ` Keir Fraser
2010-05-03 16:29 ` Keir Fraser
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