Re: [Qemu-devel] [PATCH 02/15] colo-compare: implement the process of checkpoint

[Zhang Chen]

On 02/23/2017 09:02 AM, Hailiang Zhang wrote:
> Hi,
>
> On 2017/2/22 17:31, Zhang Chen wrote:
> > On 02/22/2017 11:42 AM, zhanghailiang wrote:
> > > While do checkpoint, we need to flush all the unhandled packets,
> > > By using the filter notifier mechanism, we can easily to notify
> > > every compare object to do this process, which runs inside
> > > of compare threads as a coroutine.
> >
> > Hi~ Jason and Hailiang.
> >
> > I will send a patch set later about colo-compare notify mechanism for
> > Xen like this patch.
> > I want to add a new chardev socket way in colo-comapre connect to Xen
> > colo, for notify
> > checkpoint or failover, Because We have no choice to use this way
> > communicate with Xen codes.
> > That's means we will have two notify mechanism.
> > What do you think about this?
>
> I don't think you need another mechanism, what you need to do is to
> realize a qmp command which calls colo_notify_compares_event(),
> It will not  return until the event (checkpoint or failover) be
> handled by all compares. Will this satisfy your requirement ?

No, colo-frame notify colo-comapre can calls colo_notify_compares_event(),
That's OK, but colo-comapre notify colo-frame in Xen have some problem,
Xen's colo-frame needs a API that blocking and have a timeout to read 
colo-comapre's
notify, this timeout is the time of periodic checkpoint. In this patch set,
colo-compare just call colo_compare_inconsistent_notify() to 
non-blocking notify.
We can not realize a qmp command that Xen always polling that to get 
status of notify,
Qemu also can not accept to call qmp command for polling.


Thanks
Zhang Chen

> Thanks,
> Hailiang
>
> > Thanks
> > Zhang Chen
> >
> > > Cc: Jason Wang <address@hidden>
> > > Signed-off-by: zhanghailiang <address@hidden>
> > > Signed-off-by: Zhang Chen <address@hidden>
> > > ---
> > >    net/colo-compare.c | 72 
> > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > >    net/colo-compare.h | 20 +++++++++++++++
> > >    2 files changed, 92 insertions(+)
> > >    create mode 100644 net/colo-compare.h
>
>
>
> .

--
Thanks
Zhang Chen