30/06/2017 15:24, Van Haaren, Harry: > From: Jerin Jacob [mailto:jerin.ja...@caviumnetworks.com] > > From: "Van Haaren, Harry" <harry.van.haa...@intel.com> > > > From: Jerin Jacob [mailto:jerin.ja...@caviumnetworks.com] > > > > From: "Van Haaren, Harry" <harry.van.haa...@intel.com> > > > <snip previous non-related items> > > > > > > > > I don't think providing a remote-launch API is actually beneficial. > > > > > Remote-launching > > a > > > > single service > > > > > is equivalent to adding that lcore as a service-core, and mapping it > > > > > to just that > > single > > > > service. > > > > > The advantage of adding it as a service core, is future-proofing for > > > > > if more > > services > > > > need to be added > > > > > to that core in future, and statistics of the service core > > > > > infrastructure. A > > convenience > > > > API could be > > > > > provided to perform the core_add(), service_start(), > > > > > enable_on_service() and > > > > core_start() APIs in one. > > > > > > > > > > Also, the remote_launch API doesn't solve the original problem - what > > > > > if an > > application > > > > lcore wishes > > > > > to run one iteration of a service "manually". The remote_launch style > > > > > API does not > > solve > > > > this problem. > > > > > > > > Agree with problem statement. But, remote_launch() operates on lcores > > > > not on > > > > not necessary on 1:1 mapped physical cores. > > > > > > > > By introducing "rte_service_iterate", We are creating a parallel > > > > infrastructure to > > > > run the service on non DPDK service lcores aka normal lcores. > > > > Is this really required? Is there any real advantage for > > > > application not use builtin service lcore infrastructure, rather than > > > > iterating over > > > > "rte_service_iterate" and run on normal lcores. If we really want to mux > > > > a physical core to N lcore, EAL already provides that in the form of > > > > threads. > > > > > > > > I think, providing too many parallel options for the same use case may > > > > be > > > > a overkill. > > > > > > > > Just my 2c. > > > > > > > > > The use-case that the rte_service_iterate() caters for is one where the > > > application > > > wishes to run a service on an "ordinary app lcore", together with an > > > application > > workload. > > > > > > For example, the eventdev-scheduler and one worker can be run on the same > > > lcore. If the > > schedule() running thread *must* be a service lcore, we would not be able > > to also use that > > lcore as an application worker core. > > > > > > That was my motivation for adding this API, I do agree with you above; it > > > is a second > > "parallel" method to run a service. I think there's enough value in > > enabling the use-case > > as per example above to add it. > > > > > > > > > Do you see enough value in the use-case above to add the API? > > > > The above use case can be realized like --lcores='(0-1)@1'(Two lcore on > > an physical core). I believe, application writers never want to write a > > code based on specific number of cores available in the system. If they > > do then they will be stuck on running on another environment and too > > many combination to address. > > Good point. > > > For me it complicates service lcore usage. But someone think, it will > > useful then > > I don't have strong objection. > > We can easily add APIs later - and removing them isn't so easy. +1 from me > leave it out for now, and we can see about adding it for 17.11 if the need > arises. > > Thanks for your input, I'll spin a v3 without the rte_service_iterate() > function, and that should be it then!
I agree to leave it and keep things simple.
