On Wed, 2013-06-19 at 17:19 +0000, Love, Robert W wrote: > > From: Vasu Dev [mailto:[email protected]] > > Sent: Wednesday, June 19, 2013 10:17 AM > > To: Love, Robert W > > > > On Tue, 2013-06-18 at 10:56 -0700, Robert Love wrote: > > > fcoe_xmit was coded such that it would skip the vlan net device/layer > > > and instead set some vlan flags and transmit on the real net device. > > > The real net device has code that would add the vlan tag for fcoe skbs. > > > This avoids some extra processing for data frames and provides a small > > > performance improvement. > > > > > > > Given it was small performance gain and that too while ago, to my > > recollection it was just 25K w/ only small size IOs. Now with newer > > platforms > > this may not noticeable with significantly higher net IOPS. > > Also skipping VLAN layer violates layering as patch adds VLAN tag while > > using > > real dev, so instead I suggest just always use the device on which FCoE > > exist > > and that would use vlan and real dev correctly according to FCoE instance > > created on them to tag or not per underlying device in use. > > > > This will make FCoE stack agonistic of VLAN or real device on TX path and > > would also eliminate any such issue as this one fixed by the patch in the > > future, I mean FCoE would go thru VLAN layer to inherit any changes to vlan > > layer instead by-passing vlan layer and not aware of any such changes to > > vlan > > layer/driver. > > My thought regarding this was that since we're so late in the -rc cycle, I > didn't > want to change the behavior, I only fix the failure. > > I'm fine with transmitting using the VLAN device in the future especially if > the > author of the VLAN device skipping is happy with going back to the VLAN > device. >
I'm fine as author of that change as I'm suggesting to go thru vlan for reasons listed above. Deferring is ok though it would be even smaller change than the patch here to fix the issue as change is to simply use fcoe netdev whether vlan or real dev instead added vlan_put_tag use by the patch. //Vasu _______________________________________________ fcoe-devel mailing list [email protected] http://lists.open-fcoe.org/mailman/listinfo/fcoe-devel
