Re: [Xen-devel] [PATCH 1/2] PV hugepages - Xen patch

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

On 8/10/08 19:28, "Dave McCracken" <dcm@xxxxxxxx> wrote:

>> Actually this is an interesting one. For a PV guest it may be in general
>> unsolvable, since the target machine may not have allocatable 2MB extents.
>> It may also screw live migration since 2MB is a very coarse granularity to
>> do dirty-page tracking. One option: perhaps the PV kernel could shatter and
>> then reconstruct (as best it can) superpage mappings across save/restore?
>> I'm actually not sure what's for the best here. Perhaps just make 2MB
>> mappings and save/restore mutually exclusive for now?
> 
> Yeah, that's what I'm finding.  I think it's a good idea to document for now
> that hugepages don't work with save/restore.  I'll continue to dig into it
> and try to figure out a scheme to make it work as a future enhancement.

Then PV superpage support must be a configuration option, and disabled by
default.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel