Re: [Qemu-devel] [PATCH v4 42/47] Don't sync dirty bitmaps in postcopy

[David Gibson]

On Fri, Oct 03, 2014 at 06:47:48PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
> 
> Once we're in postcopy the source processors are stopped and memory
> shouldn't change any more, so there's no need to look at the dirty
> map.
> 
> There are two notes to this:
>   1) If we do resync and a page had changed then the page would get
>      sent again, which the destination wouldn't allow (since it might
>      have also modified the page)
>   2) Before disabling this I'd seen very rare cases where a page had been
>      marked dirtied although the memory contents are apparently identical

It would be nice to understand how that happened.

> Signed-off-by: Dr. David Alan Gilbert <address@hidden>

Otherwise,

Reviewed-by: David Gibson <address@hidden>

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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