Per ticket #3108, there were still some unfortunate bugs in the affinity code in 1.6. :-(
These have now been fixed. ...but since is the 2nd or 3rd time we have "fixed" the 1.5/1.6 series w.r.t. processor affinity, I'd really like people to test this stuff before it's committed and we ship 1.6.1. I've put tarballs containing the fixes here:
Can you please try mpirun options like --bind-to-core and --bind-to-socket and ensure that they still work for you? (even on machines with hyperthreading enabled, if you have access to such things)
IBM: I'd particularly like to hear that we haven't made anything worse on POWER systems. Thanks.
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