On Thu, Nov 21, 2013 at 02:36:59PM -0800, Jarno Rajahalme wrote: > > On Nov 21, 2013, at 1:55 PM, Ben Pfaff <b...@nicira.com> wrote: > > > On Fri, Nov 15, 2013 at 03:12:18PM -0800, Jarno Rajahalme wrote: > >> Allowing the packet to be modified by execution allows less data > >> copying for userspace action execution. Some users of the > >> dpif_execute already expect that the packet may be modified. This > >> patch makes this behavior uniform and makes the userspace datapath and > >> the execution helpers modify the packet as it is being executed. > >> Userspace action now steals the packet if given permission, as the > >> packet is normally not needed after it. The only exception is the > >> sample action, and this is accounted for my keeping track of any > >> actions that could be following the userspace action. > >> > >> The packet in dpif_upcall is changed from a pointer to a struct, > >> allowing the packet to be honest about it's headroom. After this > >> change the packet can safely be pushed on over the precarious 4 byte > >> limit earlier allowed by the netlink data preceding the packet. > >> > >> Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com> > > > > I'm having a little of a hard time figuring out where to start here. > > When you say "allow execute to modify the packet", do you mean the > > odp_execute_actions() function specifically? It would be handy to add > > a function-level comment to that function so that it becomes clear > > what it is allowed to do. > > I guess it starts from dpif_execute, and the execute members of each > dpif class. Also the dpif execute helpers, and then > odp_execute_actions(). I think I added comments to the dpif > interface, but it seems I forgot to add a comment to > odp_execute_actions(). The packet parameter is no longer a const, > though, which should be a subtle hint to the effect that the packet > can be modified.
Thanks > Otherwise? Well, now that I understand better I'll continue review. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
