Hi Chiming in on this conversation, we have a few questions/concerns with some of the responses we received from you. >> >> If you really want the old netloc API now, you could try hwloc 2.x with >> the old netloc. But that's certainly not maintained anymore, and that >> only works for IB while the new netloc should have OPA and Cray support >> soon.
— I tried building older netloc with hwloc 2.0 and it throws compiler errors. Note that netloc was cloned from it’s git repo. >> >> The plan should rather be to tell us what you need from netloc so that >> we can reenable it with a good API. We hear lots of people saying they >> are interested in netloc, but *nobody* ever told us anything about what >> they want to do for real. And I am not even sure anybody ever played >> with the old API. This software cannot go forward unless we know where >> it's going. There are many ways to design the netloc API. — At this point, our requirement is to expose graph construction from raw topology xml and mapping and traversal at best. I see some of these already defined in private/hwloc.h in the newer version. Our problem here Is that we couldn’t build it in embedded mode, which is how we are using hwloc. > On Apr 4, 2018, at 9:13 AM, Balaji, Pavan <bal...@anl.gov> wrote: > > Brice, > > We don't actually care if it is a graph or a different API. We'll anyway > simply parse the graph and create our own internal structures that we can map > to our internal algorithms. We simply need some model (any model) to > retrieve the network topology. That's it. We'll take care of everything > else in MPICH. > > -- Pavan > >> On Apr 4, 2018, at 12:46 AM, Brice Goglin <brice.gog...@inria.fr> wrote: >> >> If you really want the old netloc API now, you could try hwloc 2.x with >> the old netloc. But that's certainly not maintained anymore, and that >> only works for IB while the new netloc should have OPA and Cray support >> soon. >> >> The plan should rather be to tell us what you need from netloc so that >> we can reenable it with a good API. We hear lots of people saying they >> are interested in netloc, but *nobody* ever told us anything about what >> they want to do for real. And I am not even sure anybody ever played >> with the old API. This software cannot go forward unless we know where >> it's going. There are many ways to design the netloc API. >> >> * We had an explicit graph API in the old netloc but that API implied >> expensive graph algorithmics in the runtimes using it. It seemed >> unusable for taking decision at runtime anyway, but again ever nobody >> tried. Also it was rather strange to expose the full graph when you know >> the fabric is a 3D dragonfly on Cray, etc. >> >> * In the new netloc, we're thinking of having higher-level implicit >> topologies for each class of fabric (dragon-fly, fat-tree, clos-network, >> etc) that require more work on the netloc side and easier work in the >> runtime using it. However that's less portable than exposing the full >> graph. Not sure which one is best, or if both are needed. >> >> * There are also issues regarding nodes/links failure etc. How do we >> expose topology changes at runtime? Do we have a daemon running as root >> in the background, etc? >> >> Lots of question that need to be discussed before we expose a new API In >> the wild. Unfortunately, we lost several years because of the lack of >> users' feedback. I don't want to invest time and rush for a new API if >> MPICH never actually uses it like other people did in the past. >> >> Brice >> >> >> >> >> Le 04/04/2018 à 01:36, Balaji, Pavan a écrit : >>> Brice, >>> >>> We want to use both hwloc and netloc in mpich. What are our options here? >>> Move back to hwloc-1.x? That’d be a bummer because we already invested a >>> lot of effort to migrate to hwloc-2.x. >>> >>> — Pavan >>> >>> Sent from my iPhone >>> >>>> On Apr 3, 2018, at 6:19 PM, Brice Goglin <brice.gog...@inria.fr> wrote: >>>> >>>> It's not possible now but that would certainly be considered whenever >>>> people start using the API and linking against libnetloc. >>>> >>>> Brice >>>> >>>> >>>> >>>> >>>>> Le 03/04/2018 à 21:34, Madhu, Kavitha Tiptur a écrit : >>>>> Hi >>>>> A follow up question, is it possible to build netloc along with hwloc in >>>>> embedded mode? >>>>> >>>>> >>>>>> On Mar 30, 2018, at 1:34 PM, Brice Goglin <brice.gog...@inria.fr> wrote: >>>>>> >>>>>> Hello >>>>>> >>>>>> In 2.0, netloc is still highly experimental. Hopefully, a large rework >>>>>> will be merged in git master next month for being released in hwloc 2.1. >>>>>> >>>>>> Most of the API from the old standalone netloc was made private when >>>>>> integrated in hwloc because there wasn't any actual user. The API was >>>>>> quite large (things for traversing the graph of both the fabric and the >>>>>> servers' internals). We didn't want to expose such a large API before >>>>>> getting actual user feedback. >>>>>> >>>>>> In short, in your need features, please let us know, so that we can >>>>>> discuss what to expose in the public headers and how. >>>>>> >>>>>> Brice >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>> Le 30/03/2018 à 20:14, Madhu, Kavitha Tiptur a écrit : >>>>>>> Hi >>>>>>> >>>>>>> I need some info on the status of netloc integration with hwloc. I see >>>>>>> the include/netloc.h header is almost empty in hwloc 2.0 and lots of >>>>>>> functionality missing compared to the previous standalone netloc >>>>>>> release, even in private/netloc.h. Am I missing something here? >>>>>>> >>>>>>> Thanks >>>>>>> Kavitha >>>>>>> >>>>>> _______________________________________________ >>>>>> hwloc-users mailing list >>>>>> hwloc-users@lists.open-mpi.org >>>>>> https://lists.open-mpi.org/mailman/listinfo/hwloc-users >>>>> _______________________________________________ >>>>> hwloc-users mailing list >>>>> hwloc-users@lists.open-mpi.org >>>>> https://lists.open-mpi.org/mailman/listinfo/hwloc-users >>>> _______________________________________________ >>>> hwloc-users mailing list >>>> hwloc-users@lists.open-mpi.org >>>> https://lists.open-mpi.org/mailman/listinfo/hwloc-users >>> _______________________________________________ >>> hwloc-users mailing list >>> hwloc-users@lists.open-mpi.org >>> https://lists.open-mpi.org/mailman/listinfo/hwloc-users >> >> _______________________________________________ >> hwloc-users mailing list >> hwloc-users@lists.open-mpi.org >> https://lists.open-mpi.org/mailman/listinfo/hwloc-users > > _______________________________________________ > hwloc-users mailing list > hwloc-users@lists.open-mpi.org > https://lists.open-mpi.org/mailman/listinfo/hwloc-users _______________________________________________ hwloc-users mailing list hwloc-users@lists.open-mpi.org https://lists.open-mpi.org/mailman/listinfo/hwloc-users
