Re: [Qemu-devel] [PATCH 1/4] net/colo-compare.c: Add checkpoint min period to optimize performance

[Zhang Chen]

On 07/07/2017 02:06 PM, Li Zhijian wrote:
> On 07/07/2017 01:43 PM, Zhang Chen wrote:
> > If colo-compare find out the first different packet
>
> at this situation, why not trigger the checkpoint, and then flush all 
> primary packets and drop secondary packets?

In this time we already do this job, but before this checkpoint to be done,
a lot of checkpoint has been triggered. It is no sense do many 
checkpoint in very short time.
So we just need do once checkpoint in this situation.

Thanks
Zhang Chen

> >   that means
> > the following packet almost is different. we needn't do a lot
> > of checkpoint in this time, so we set the no-need-checkpoint
> > peroid, default just set 3 second.
> >
> > Signed-off-by: Zhang Chen <address@hidden>
> > ---
> >   net/colo-compare.c | 13 ++++++++++++-
> >   1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/colo-compare.c b/net/colo-compare.c
> > index 6d500e1..0f8e198 100644
> > --- a/net/colo-compare.c
> > +++ b/net/colo-compare.c
> > @@ -40,6 +40,9 @@
> >   /* TODO: Should be configurable */
> >   #define REGULAR_PACKET_CHECK_MS 3000
> >   +/* TODO: Should be configurable */
> > +#define CHECKPOINT_MIN_TIME 3000
> > +
> >   /*
> >     + CompareState ++
> >     |               |
> > @@ -455,6 +458,7 @@ static void colo_compare_connection(void *opaque, 
> > void *user_data)
> >       Packet *pkt = NULL;
> >       GList *result = NULL;
> >       int ret;
> > +    static int64_t checkpoint_time_ms;
> >         while (!g_queue_is_empty(&conn->primary_list) &&
> >              !g_queue_is_empty(&conn->secondary_list)) {
> > @@ -494,7 +498,14 @@ static void colo_compare_connection(void 
> > *opaque, void *user_data)
> >                */
> >               trace_colo_compare_main("packet different");
> >               g_queue_push_tail(&conn->primary_list, pkt);
> > -            /* TODO: colo_notify_checkpoint();*/
> > +
> > +            if (pkt->creation_ms - checkpoint_time_ms > 
> > CHECKPOINT_MIN_TIME) {
> > +                /*
> > +                 * TODO: Notify colo frame to do checkpoint.
> > +                 * colo_compare_inconsistent_notify();
> > +                 */
> > +                checkpoint_time_ms = pkt->creation_ms;
> > +            }
> >               break;
> >           }
> >       }

--
Thanks
Zhang Chen