On Tue 19 Feb 2019 at 05:26, Cong Wang <xiyou.wangc...@gmail.com> wrote: > On Fri, Feb 15, 2019 at 7:35 AM Vlad Buslov <vla...@mellanox.com> wrote: >> >> Another problem that I found in cls_fw and cls_route is that they set >> arg->stop when empty. Both of them have code unchanged since it was >> committed initially in 2005 so I assume this convention is no longer >> relevant because all other classifiers don't do that (they only set >> arg->stop when arg->fn returns negative value). >> > > The question is why do you want to use arg->stop==0 as > an indication for emptiness? Isn't what arg->count==0 > supposed to be?
Good question! I initially wanted to implement it like that, but reconsidered because iterating through all filters on classifier to count them is O(N), and terminating on first filter and relying on arg->stop==1 is constant time. Making function that is called "tcf_proto_is_empty" linear on number of filters seemed sloppy to me...
