Wed, Jun 27, 2018 at 08:36:24PM CEST, jakub.kicin...@netronome.com wrote: >On Wed, 27 Jun 2018 09:50:17 +0200, Jiri Pirko wrote: >> Tue, Jun 26, 2018 at 11:18:58PM CEST, jakub.kicin...@netronome.com wrote: >> >On Tue, 26 Jun 2018 09:12:17 +0200, Jiri Pirko wrote: >> >> Tue, Jun 26, 2018 at 09:00:45AM CEST, jakub.kicin...@netronome.com wrote: >> >> >> >> >On Mon, Jun 25, 2018 at 11:43 PM, Jiri Pirko <j...@resnulli.us> wrote: >> >> > >> >> >> Tue, Jun 26, 2018 at 06:58:50AM CEST, jakub.kicin...@netronome.com >> >> >> wrote: >> >> >>>On Mon, 25 Jun 2018 23:01:39 +0200, Jiri Pirko wrote: >> >> >>>> From: Jiri Pirko <j...@mellanox.com> >> >> >>>> >> >> >>>> For the TC clsact offload these days, some of HW drivers need >> >> >>>> to hold a magic ball. The reason is, with the first inserted rule >> >> >>>> inside >> >> >>>> HW they need to guess what fields will be used for the matching. If >> >> >>>> later on this guess proves to be wrong and user adds a filter with a >> >> >>>> different field to match, there's a problem. Mlxsw resolves it now >> >> >>>> with >> >> >>>> couple of patterns. Those try to cover as many match fields as >> >> >>>> possible. >> >> >>>> This aproach is far from optimal, both performance-wise and >> >> >>>> scale-wise. >> >> >>>> Also, there is a combination of filters that in certain order won't >> >> >>>> succeed. >> >> >>>> >> >> >>>> Most of the time, when user inserts filters in chain, he knows right >> >> >>>> away >> >> >>>> how the filters are going to look like - what type and option will >> >> >>>> they >> >> >>>> have. For example, he knows that he will only insert filters of type >> >> >>>> flower matching destination IP address. He can specify a template >> >> >>>> that >> >> >>>> would cover all the filters in the chain. >> >> >>> >> >> >>>Perhaps it's lack of sleep, but this paragraph threw me a little off >> >> >>>the track. IIUC the goal of this set is to provide a way to inform the >> >> >>>HW about expected matches before any rule is programmed into the HW. >> >> >>>Not before any rule is added to a particular chain. One can just use >> >> >>>the first rule in the chain to make a guess about the chain, but thanks >> >> >>>to this set user can configure *all* chains before any rules are >> >> >>>added. >> >> >> >> >> >> The template is per-chain. User can use template for chain x and >> >> >> not-use it for chain y. Up to him. >> >> > >> >> >Makes sense. >> >> > >> >> >I can't help but wonder if it'd be better to associate the >> >> >constraints/rules with chains instead of creating a new "template" >> >> >object. It seems more natural to create a chain with specific >> >> >constraints in place than add and delete template of which there can >> >> >be at most one to a chain... Perhaps that's more about the user space >> >> >tc command line. Anyway, not a strong objection, just a thought. >> >> >> >> Hmm. I don't think it is good idea. User should see the template in a >> >> "show" command per chain. We would have to have 2 show commands, one to >> >> list the template objects and one to list templates per chains. It makes >> >> things more complicated for no good reason. I think that this simple >> >> chain-lock is easier and serves the purpose. >> > >> >Hm, I think the dump is fine, what I was thinking about was: >> > >> ># tc chain add dev dummy0 ingress chain_index 22 \ >> > ^^^^^ >> > template proto ip \ >> > ^^^^^^^^ >> > flower dst_mac 00:00:00:00:00:00/00:00:00:00:FF:FF >> >> Okay, I got it. I see 2 issues. >> 1) user might expect to add a chain without the template. But that does >> not make sense really. Chains are created/deleted implicitly >> according to refcount. >> 2) there is not chain object like this available to user. Adding it just >> for template looks odd. Also, the "filter" and "template" are very >> much alike. They both are added to a chain, they both implicitly >> create chain if it does not exist, etc. > >Yeah, that part makes is tricky :/ > >> if you don't like "tc filter template add dev dummy0 ingress", how >> about: >> "tc template add dev dummy0 ingress ..." >> "tc template add dev dummy0 ingress chain 22 ..." >> that makes more sense I think. > >Mmm.. how about: > > tc chaintemplate add dev dummy0 ingress...
This looks fine to me. > >or > > tc restrictedchain add dev dummy0 ingress chain_index XX template ...
