On Thu, Sep 2, 2010 at 5:05 PM, Ira Weiny <wei...@llnl.gov> wrote: > On Thu, 2 Sep 2010 13:35:44 -0700 > Hal Rosenstock <hal.rosenst...@gmail.com> wrote: > >> Hi Ira, >> >> On Tue, Aug 31, 2010 at 3:49 PM, Ira Weiny <wei...@llnl.gov> wrote: >> > On Tue, 31 Aug 2010 02:27:29 -0700 >> > Yevgeny Kliteynik <klit...@gmail.com> wrote: >> > >> >> Hi all, >> >> >> >> In order to support RoCEE, a while ago I've added >> >> a new field to umad, thus introduced an ABI change. >> >> >> >> There already was a discussion on the linux-rdma list, >> >> but due to the proximity of the upcoming OFED 1.5.2 >> >> release these concerns were raised again. >> >> >> >> So my question is, other that *general* concerns about >> >> changing ABI, is anybody aware of the *actual* problem >> >> that will be caused by this? Any customer/3rd party >> >> solution that would be affected by this? >> > >> > Because our MVAPICH depends on umad, libibumad.so.1 to be exact.[*] These >> > ABI >> > changes (to v2 and v3) would have forced our users to recompile their >> > codes. >> > We are maintaining the old ABI here until our next major release of >> > CHAOS[#] >> > to prevent this. >> > >> > I think the thing to remember is that many people are using Open Fabrics >> > software, but are _not_ using "OFED". What is tested with OFED is not the >> > only thing which might be using these libraries. Our version of MVAPICH >> > is a >> > good example. >> > >> > I am certainly not the expert in this area and I know that many people have >> > tried to make this point in the past, but I will say it here again. Each >> > of >> > these Open Fabrics packages _must_ be maintained to stand on their own. >> > Roland did this a long time ago with ibverbs. >> > >> > I think now is a good time to start discussing breaking up the >> > "management" git >> > tree so that these libraries can live on their own. >> >> How does breaking up the "management" git tree help with this issue ? > > Creating and tracking of branches to maintain ABI would be easier with > separate git trees. Furthermore, separate trees will help "force" the use of > consistent ABI's and interfaces. > > For example, if I currently want OpenSM version 3.3.6 I get a management tree > with version libibumad 1.3.5. But this last ABI change to umad was only > required for the latest infiniband-diags (ibstat utility). Why do I get all > this "cruft" when pulling the latest OpenSM?
That's a totally different issue than which packages a particular OFED release picks up. > >> To me, that's the admin part and is separate from the ABI issue >> raised. > > Yes it is separate. That is why I created another thread to discuss those > issues. > >> >> The ABI compatibility is not achieved by administrative means >> (separate repos, etc.) but rather than review and discipline to >> achieve this as a unmutable goal. > > I agree that ABI compatibility will require more discipline. That is what > made me think of the separate git trees. I feel it will be _easier_ to > maintain this discipline when the trees are separate. Call me a skeptic but I think the same thing would've occurred with separate git trees. I have no real preference one way or the other. In fact, this was discussed in the early days which are long forgotten. The libraries are small and umad is a lot more stable than mad. It would just mean a lot of busy work for everyone with internal trees. -- Hal > > Ira > >> >> -- Hal >> >> > I will write a separate email regarding this. >> > >> > Ira >> > >> > [*] We are looking into removing the dependency. >> > [#] Shameless plug: >> > http://*code.google.com/p/chaos-release/wiki/CHAOS_Description >> > >> >> >> >> -- Yevgeny >> >> -- >> >> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in >> >> the body of a message to majord...@vger.kernel.org >> >> More majordomo info at http://**vger.kernel.org/majordomo-info.html >> >> >> > >> > >> > -- >> > Ira Weiny >> > Math Programmer/Computer Scientist >> > Lawrence Livermore National Lab >> > 925-423-8008 >> > wei...@llnl.gov >> > -- >> > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in >> > the body of a message to majord...@vger.kernel.org >> > More majordomo info at http://*vger.kernel.org/majordomo-info.html >> > >> > > > -- > Ira Weiny > Math Programmer/Computer Scientist > Lawrence Livermore National Lab > 925-423-8008 > wei...@llnl.gov > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
