Hi Numan, Dumitru

Thanks for your feedback and sorry for the confusion.
Comment embedded below.

Thanks
Xavier

On Mon, Dec 23, 2024 at 12:58 PM Dumitru Ceara <[email protected]> wrote:

> On 12/20/24 10:31 PM, Numan Siddique wrote:
> > On Thu, Nov 14, 2024 at 8:58 AM Xavier Simonart <[email protected]>
> wrote:
> >> Signed-off-by: Xavier Simonart <[email protected]>
> >> ---
> >>  controller/physical.c | 15 ++++++++++++---
> >>  1 file changed, 12 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/controller/physical.c b/controller/physical.c
> >> index 8d5065098..6b93696fa 100644
> >> --- a/controller/physical.c
> >> +++ b/controller/physical.c
> >> @@ -2194,15 +2194,15 @@ consider_mc_group(struct ovsdb_idl_index
> *sbrec_port_binding_by_name,
> >>          }
> >>
> >>          int zone_id = ct_zone_find_zone(ct_zones, port->logical_port);
> >> -        if (zone_id) {
> >> -            put_load(zone_id, MFF_LOG_CT_ZONE, 0, 16, &ofpacts);
> >> -        }
> > Hi Xavier,
> >
> > I'm a little confused with this patch.  Can you please explain what is
> > the improvement here ?
>
The goal of the patch is minor: it avoids some differences between flows
created by I+P and recompute.
Fixing this will let us (in a later patch) automatically compare I+P and
recompute flows and catch issues.

Without the patch I+P might produce flows as:
... table=43 ... priority=100,reg15=0x8000,metadata=0x1
actions=load:0->NXM_NX_REG6[],
load:0x3->NXM_NX_REG13[0..15],load:0x1->NXM_NX_REG15[],resubmit(,44),load:0x8000->NXM_NX_REG15[]
and recompute:
... table=43 ... priority=100,reg15=0x8000,metadata=0x1
actions=load:0->NXM_NX_REG6[]*,load:0x4->NXM_NX_REG13[0..15]*
,load:0x3->NXM_NX_REG13[0..15],load:0x1->NXM_NX_REG15[],resubmit(,44),load:0x8000->NXM_NX_REG15[]
So, in one case we set register REG13 twice: first it is set to 4, and then
overwritten to 3; in the other case we set it directly to 3.
Goal of the patch is to avoid the extra load:0x4->NXM_NX_REG13[0..15].

>
> > Also can you please update the commit message with more details ?
>
I'll do it if we agree that the patch makes sense.

> >
> > From what I understand prior to this patch,  for all the port bindings
> > in a multicast group,
> > zone id of the pb (if present) is loaded to the ct_zone register.
> >
> > How is this patch avoiding setting the same register again ?
>
The issue happens for some port types, such as virtual or localport.
Those ports usually have a ct-zone assigned, so we were issuing
"put_load(zone_id, MFF_LOG_CT_ZONE, 0, 16, &ofpacts);" for those ports.
However, we were not calling "local_output_pb" for those ports (so, no
resubmit), and hence the ct_zone register was either overwritten when
handling another port in the loop, or was useless (no resubmit after
setting the ct_zone register).

With the patch, we do not set the ct_zone register for those ports.

>
> > Thanks
> > Numan
>
> Hi Numan, Xavier,
>
> I marked the rest of the series as "changes requested" in patchwork.
>
> Thanks
Xavier

> Regards,
> Dumitru
>
>
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev

Reply via email to