Re: [Qemu-devel] [PATCH RESEND v2 01/18] net/colo: Add notifier/callback related helpers for filter

[Hailiang Zhang]

On 2017/4/25 19:40, Jason Wang wrote:
> On 2017年04月22日 16:35, zhanghailiang wrote:
> > We will use this notifier to help COLO to notify filter object
> > to do something, like do checkpoint, or process failover event.
> >
> > Cc: Jason Wang<address@hidden>
> > Signed-off-by: zhanghailiang<address@hidden>
> > Signed-off-by: Zhang Chen<address@hidden>
> > Signed-off-by: Li Zhijian<address@hidden>
> > ---
> >    net/colo.c | 105 
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >    net/colo.h |  19 +++++++++++
> >    2 files changed, 124 insertions(+)
> Went through this series and I feel that the code duplicates (at least
> part) functionality of IOThread (iothread.c) . So I come to an idea that,
> switch to use IOThread for COLO comparing thread then you can use aio bh
> to do the inter process communication.
>
> Thoughts?

Interesting idea, but after investigation, we found it will make things quite 
complex
if we use iothread for net compare (Actually, i don't think we can use it 
directly for COLO),
It seems to be special for block, you can see some codes call block helpers.
Besides, we still have to realize a way to communicate with COLO frame for 
filters  (I mean patch 16/17/18),
even we use it after reconstruct those iothread part. ;)

Thanks,
Hailiang

> Thanks
>
> .