On Fri, 2013-05-24 at 14:23 -0700, Jesse Gross wrote: > On Fri, May 24, 2013 at 11:58 AM, Eric Dumazet <eric.duma...@gmail.com> wrote: > > On Fri, 2013-05-24 at 10:24 -0700, Jesse Gross wrote: > > > >> Does this have any impact on small packets? Those are usually the > >> common case (i.e. TCP SYN) and I think this is slightly less optimal > >> for those. > > > > No difference at all, small packets are copied anyway in skb->head > > Yes, but it makes the Open vSwitch code slightly worse - for example, > currently checksumming and copying are done in a single step but this > prevents that. Actually, I'm also curious about the test case that was > used for large packets and the full profile output since checksumming > and GSO aren't listed in the one that Thomas gave. >
GSO is fully supported in nfnetlink, I see no reason why Open vSwitch would not allow that. > My guess is that there isn't a real different for small packets since > everything will be in the cache but it seems worth checking given that > this is optimizing a rare case at the expense of the common one. I really doubt checksumming a SYN/ACK packet is that a performance issue. Do you have performance numbers ? You could always provide a patch to restore this copy/checksum if it really gives a benefit, and if people still use NIC not doing this checksum. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
