On Nov 5, 2014, at 12:03 PM, Joshua Ladd <jladd.m...@gmail.com> wrote:
> I think this is a pretty significant change in behavior for a minor release, > Jeff. According to the interested parties: > > "I'm reporting a performance (message rate 16%, latency 3%) regression when > using PSM that occurred between OMPI v1.6.5 and v1.8.1. I would guess it > affects other networks too, but I haven't tested. The problem stems from the > --enable-smp-locks and --enable-opal-multi-threads options." Right, and we just fixed that problem. To be clear: the above report is from *before* we fixed the problem, not from *after* we fixed it. After we fixed it, Intel confirmed that PSM performance went back up to v1.6 levels. It was never in the plan to bring over the enable-THREAD_MULTIPLE-beavhior-by-default functionality to the v1.8 branch. It was a mistake that it got brought over. > So, this has been in effect the entire 1.8 series and now you want to > significantly alter the behavior. Put differently: I want to fix the performance bug. > I'm of the opinion that we should live with the mistake in the 1.8.x series > and provide users with clear guidance on the default behavior and advice for > disabling the threading support that is consistent across this series. 1.9.x > is a clean slate. I disagree. MPI_THREAD_MULTIPLE support barely works in v1.8. Why have it on by default, especially when there's a performance penalty? -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
