Re: [Qemu-devel] [PATCH 2/4] net/colo-compare.c: compare tcp packet base on sequence number

[Zhang Chen]

On 07/07/2017 02:20 PM, Li Zhijian wrote:
> this title confused me
>
> i think you want to express "only compare the packets that has the 
> same sequence number"

OK, I will fix it in next version.

> and i think this optimization can not reduce this checkpoint 
> optimization.

In my test it can reduce many full comparison(like memcmp),
and in the future we have some job about this point.

Thanks
Zhang Chen

> Thanks
>
>
> On 07/07/2017 01:43 PM, Zhang Chen wrote:
> > If primary packet's sequence number not same with secondary packet's
> > sequence number, no need to compare the packet other field.
> >
> > Signed-off-by: Zhang Chen <address@hidden>
> > ---
> >   net/colo-compare.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/net/colo-compare.c b/net/colo-compare.c
> > index 0f8e198..2caeb80 100644
> > --- a/net/colo-compare.c
> > +++ b/net/colo-compare.c
> > @@ -222,6 +222,12 @@ static int colo_packet_compare_tcp(Packet *spkt, 
> > Packet *ppkt)
> >       ptcp = (struct tcphdr *)ppkt->transport_header;
> >       stcp = (struct tcphdr *)spkt->transport_header;
> >   +    if ((ptcp->th_flags & TH_SYN) != TH_SYN &&
> > +        ptcp->th_seq != stcp->th_seq) {
> > +        trace_colo_compare_main("colo_packet_compare_tcp seq not 
> > same");
> > +        return -1;
> > +    }
> > +
> >       /*
> >        * The 'identification' field in the IP header is *very* random
> >        * it almost never matches.  Fudge this by ignoring differences in
>
> .

--
Thanks
Zhang Chen