RE: [Xen-devel] Error restoring DomU when using GPLPV

[Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>]

Before we close down this thread, I have a concern:

According to Mukesh, the fix to this bug is dependent
on the pv drivers tracking tot_pages for a domain
and ballooning to ensure tot_pages+3 does not exceed
max_pages for the domain.

Well, tmem can affect tot_pages for a domain inside
the hypervisor without any notification to pv drivers
or the balloon driver.  And I'd imagine that PoD and
future memory optimization mechanisms such as
swapping and page-sharing may do the same.

So this solution seems very fragile.

Dan

> -----Original Message-----
> From: Keir Fraser [mailto:keir.fraser@xxxxxxxxxxxxx]
> Sent: Wednesday, September 16, 2009 6:28 AM
> To: Annie Li
> Cc: Joshua West; Dan Magenheimer; xen-devel; Kurt Hackel; 
> James Harper;
> Wayne Gong
> Subject: Re: [Xen-devel] Error restoring DomU when using GPLPV
> 
> 
> On 16/09/2009 12:10, "ANNIE LI" <annie.li@xxxxxxxxxx> wrote:
> 
> >> I will do more test to make sure it and update here.
> > I tried to map 256 grant frames during initialization and 
> balloon down
> > 256+1(shinfo+gnttab) pages driver first
> > load. Then i did save/restore for 50 times, and live 
> migration for 10
> > times. No error occurs.
> 
> Okay, well I still can't explain why that fixes it, but 
> clearly it does. So
> that's good. :-)
> 
>  -- Keir
> 
> 
>

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