Re: [Qemu-devel] [PATCH 0/6] Obtain dirty bitmap via VM logging

[Sanidhya Kashyap]

On Wed, May 21, 2014 at 12:15 PM, ChenLiang <address@hidden> wrote:
> On 2014/5/21 12:56, Sanidhya Kashyap wrote:
>
>> On Wed, May 21, 2014 at 9:43 AM, ChenLiang <address@hidden> wrote:
>>> Hi,
>>> Nice job. We should avoid running migration_thread and 
>>> bitmap_logging_thread simultaneously.
>>>
>> Any particular suggestion to avoid running simultaneous execution of
>> the threads?
>>
>
> We can do it like this:
> https://lists.gnu.org/archive/html/qemu-devel/2014-04/msg02185.html
>

Hi Chen,

I have some questions which I wanted  to get clarified before
implementing the above part of avoiding the simultaneous execution.

As the migration process is going on, the RUN_STATE_RUNNING state is
being used, which is the same case in bitmap dump process. In order to
use the concept of RUN_STATE_* states, should I create two new states
as RUN_STATE_LOGBITMAP AND RUN_STATE_OUTMIGRATE? The
RUN_STATE_OUTMIGRATE state will have all the transitions that
RUN_STATE_RUNNING supports except the ones being used by migration.
Similarly, RUN_STATE_MIGRATE will support all the transitions of
RUN_STATE_RUNNING except RUN_STATE_LOGBITMAP.

We might also have to update the runstate_is_running function, since
RUN_STATE_LOGBITMAP and RUN_STATE_MIGRATE are almost similar in nature
to the RUN_STATE_RUNNING. What is your opinion about that?

Is it the only approach to do it or are there any simple and efficient
approaches?

Thanks,
Sanidhya