Wed, Nov 02, 2016 at 02:29:40PM CET, ro...@cumulusnetworks.com wrote: >On Wed, Nov 2, 2016 at 12:20 AM, Jiri Pirko <j...@resnulli.us> wrote: >> Wed, Nov 02, 2016 at 03:13:42AM CET, ro...@cumulusnetworks.com wrote: >>> >[snip] > >>>I understand..but, if you are adding some core infrastructure for switchdev >>>..it cannot be >>>based on the number of simple use-cases or data you have today. >>> >>>I won't be surprised if tomorrow other switch drivers have a case where they >>>need to >>>reset the hw routing table state and reprogram all routes again. >>>Re-registering the notifier to just >>>get the routing state of the kernel will not scale. For the long term, since >>>the driver does not maintain a cache, >> >> Driver (mlxsw, rocker) maintain a cache. So I'm not sure why you say >> otherwise. >> >> >>>a pull api with efficient use of rtnl will be useful for other such cases as >>>well. >> >> How do you imagine this "pull API" should look like? > > >Just like you already have added fib notifiers to parallel fib netlink >notifications, the pull API is a parallel to 'netlink dump'. >Is my imagination too wild ? :)
Perhaps I'm slow, but I don't understand what you mean. > > >> >> >>> >>> >>>If you don't want to get to the complexity of a new api right away because >>>of the >>>simple case of management interface routes you have, Can your driver >>>register the notifier early ? >>>(I am sure you have probably already thought about this) >> >> Register early? What it would resolve? I must be missing something. We >> register as early as possible. But the thing is, we cannot register >> in a past. And that is what this patch resolves. > >sure, you must be having a valid problem then. I was just curious why >your driver is not up and initialized before any of the addresses or >routes get configured in the system (even on a management port). Ours If you unload the module and load it again for example. This is a valid usecase. >does. But i agree there can be races and you cannot always guarantee >(I was just responding to ido's comment about adding complexity for a >small problem he has to solve for management routes). Our driver does >a pull before it starts. This helps when we want to reset the hardware >routing table state too. Can you point me to you driver in the tree? I would like to see how you do "the pull". > > >But, my point was, when you are defining an API, you cannot quantify >the 'past' to be just the very 'close past' or 'the past is just the >management routes that were added' . Tomorrow the 'past' can be the >full routing table if you need to reset the hardware state. Sure.
