Re: [PATCH 00 of 10] Teach xm save to checkpoint a

[Brendan Cully <brendan@cs.ubc.ca>]

On Wednesday, 20 December 2006 at 19:01, Yoshiaki Tamura wrote:
> Brendan:
> 
> Hi, my name is Yoshi Tamura, working for NTT Labs in Japan.
> I tried your patches, and I liked your new feature to checkpoint a running 
> domain.
> I also tried your patches for live migration, but xc_linux_restore() on the 
> remote machine failed.
> I track downed the problem and fixed it by modifying __xen_checkpoint() in 
> machine_reboot.c. Take a look at the following patch.
> As far as I have tested, it works for both xm save -c and xm migrate 
> –live.
> Let me know if you have any comments or better idea.

Hi Yoshi,

sorry for the late reply - I went on vacation shortly after your
post. I'm working on incorporating Keir's feedback at the moment,
which seems to include your suggestion. I'll post a new patch series
soon.

By the way, how were you doing checkpointed live migration? Didn't the
old and new domains fight over the network and block devices?

> Regards,
> 
> Yoshi Tamura
> 
> 
> Signed-off-by: Yoshi Tamura <tamura.yoshiaki@lab.ntt.co.jp>
> 
> diff -r 3bde632518a4 linux-2.6-xen-sparse/drivers/xen/core/machine_reboot.c
> 23:05:42 2006 -0800
> +++ b/linux-2.6-xen-sparse/drivers/xen/core/machine_reboot.c	Wed Dec 20 
> 16:21:43 2006 +0900
> @@ -171,8 +171,6 @@ int __xen_suspend(void)
> 
>  	pre_suspend();
> 
> -	gnttab_checkpoint();
> -
>  	/*
>  	 * We'll stop somewhere inside this hypercall. When it returns,
>  	 * we'll start resuming after the restore.
> @@ -223,6 +221,8 @@ int __xen_checkpoint(void)
> 
>  	xenbus_lock();
> 
> +	gnttab_suspend();
> +
>  	preempt_disable();
> 
>  	mm_pin_all();
> @@ -257,6 +257,8 @@ int __xen_checkpoint(void)
>  	} else {
>  		post_checkpoint();
> 
> +		gnttab_resume();
> +
>  		local_irq_enable();
> 
>  		xenbus_unlock();
> 
> 
>