> -----Original Message----- > From: Van Haaren, Harry > Sent: Tuesday, June 6, 2017 4:41 PM > To: Ananyev, Konstantin <konstantin.anan...@intel.com>; Richardson, Bruce > <bruce.richard...@intel.com> > Cc: dev@dpdk.org; Thomas Monjalon <tho...@monjalon.net>; Jerin Jacob > <jerin.ja...@caviumnetworks.com>; Wiles, Keith > <keith.wi...@intel.com> > Subject: RE: [dpdk-dev] [RFCv2] service core concept > > > From: Ananyev, Konstantin > > Sent: Tuesday, June 6, 2017 4:29 PM > > Subject: RE: [dpdk-dev] [RFCv2] service core concept > > > > > > > From: Richardson, Bruce > > > Sent: Tuesday, June 6, 2017 3:54 PM > > > > > > On Tue, Jun 06, 2017 at 11:25:57AM +0100, Van Haaren, Harry wrote: > > > > > From: Ananyev, Konstantin > > > > > Sent: Saturday, June 3, 2017 11:23 AM > > > > > > > > <snip> > > <snip other discussion> > > > > > > > > > There are a number of options here, each with its own merit: > > > > > > > > A) Services/cores config in EAL > > > > Benefit is that service functionality can be transparent to the > > > > application. Negative is > > that the complexity is in EAL. > > > > > > > > B) Application configures services/cores > > > > Benefit is no added EAL complexity. Negative is that application code > > > > has to configure > > cores (duplicated per application). > > > > > > > > > > > > To answer this question, I think we need to estimate how many > > > > applications would benefit > > from EAL integration and balance that against > > > the "complexity cost" of doing so. I do like the simplicity of option > > > (B), however if there > > is significant value in total transparency to the > > > application I think (A) is the better choice. > > > > > > > > > > > > Input on A) or B) welcomed! -Harry > > > > > > I'm definitely in favour of having it in EAL. The whole reason for doing > > > this work is to make it easy for applications to dedicate cores to > > > background tasks - including applications written before this > > > functionality was added. By merging this into EAL, we can have > > > transparency in the app, as we can have the service cores completely in > > > the background, and the app can call rte_eal_mp_remote_launch() exactly > > > as before, without unexpected failures. If we move this externally, the > > > app needs to be reworked to take account of that fact, and call new, > > > service-core aware, launch functions instead. > > > > Not sure I understood you here: > > If the app don' plan to use any cores for services, it for sure will be > > able to call > > rte_eal_mp_remote_launch() as before (no services running case). > > Correct - EAL behavior remains unchanged if --service-cores=0xf is not passed > > > > From other side, if the app would like to use services - it would need to > > specify > > which service it wants to run, and for each service provide a coremask, > > even if > > EAL already allocates service cores for it. > > See next paragraph > > > > Or are you talking about the when EAL allocates service cores, and then > > PMDs themselves (or EAL again) register their services on that cores? > > EAL could provide sane default behavior. For example, round-robin services > over available service-cores. Multithread-capable services can > be registered on all service cores. Its not a perfect solution for all > service-to-core mapping problems, but I'd guess about 80% of cases > would be covered: using a single service with a single service core dedicated > to it :) > > > > That's probably possible, but how PMD would know which service core(s) it > > allowed to use? > > The PMD shouldn't be deciding - EAL for basic sanity config, or Application > for advanced usage. > > > > Things might get over-complicated here - in theory there could be multiple > > PMDs, > > each of them can have more than one service, running on multiple sets of > > cores, etc. > > True - the NxM service:core mapping possibility can be huge - the API allows > the application the flexibility if that flexibility is really required. > If the flexibility is not required, the round-robin 1:1 service:core EAL > scheme should cover it?
Ok, so if I understand you right: by default EAL will allow each PMD to register it's services on all available service cores? Konstantin
