Re: [PATCH v6 COLO 02/15] secondary vm suspend/resume/checkpoint code

[Yang Hongyang <yanghy@cn.fujitsu.com>]

Hi Ian J, Wei,

On 06/12/2015 10:51 PM, Ian Jackson wrote:
> Wei Liu writes ("Re: [Xen-devel] [PATCH v6 COLO 02/15] secondary vm suspend/resume/checkpoint code"):
>> On Mon, Jun 08, 2015 at 11:45:46AM +0800, Yang Hongyang wrote:
>>> From: Wen Congyang <wency@cn.fujitsu.com>
>>> +    crcs->status = LIBXL_COLO_RESUMED;
>>> +
>>> +    /* avoid calling libxl__xc_domain_restore_done() more than once */
>>> +    if (crs->saved_cb) {
>>> +        dcs->callback = crs->saved_cb;
>>> +        crs->saved_cb = NULL;
>>
>> I have a feeling that this trick should be avoided. But I'm not an
>> expert on this so I will defer judgement to Ian J.
>
> Yes, this trick should be avoided.  It will make the resulting
> control flow very confusing.

I agree that this part is a bit of tricky. I will try to find another
way to do this. Maybe add another state variable to indicate what stage
we are in, the first boot or under checkpoint.

>
> Ian.
> .
>

-- 
Thanks,
Yang.