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Improving EPCC performance when linking with hwloc
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Authored by jlpeyton on Jul 7 2016, 8:55 AM.

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Summary

When linking with libhwloc, the ORDERED EPCC test slows down on big machines (> 48 cores). Performance analysis showed that a cache thrash
was occurring and this padding helps alleviate the problem.

Also, inside the main spin-wait loop in kmp_wait_release.h, we can eliminate the references to the global shared variables by instead creating a local variable, oversubscribed and instead checking that.

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rL LLVM

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jlpeyton updated this revision to Diff 63080.Jul 7 2016, 8:55 AM
jlpeyton retitled this revision from to Improving EPCC performance when linking with hwloc.
jlpeyton updated this object.
jlpeyton added reviewers: tlwilmar, AndreyChurbanov.
jlpeyton set the repository for this revision to rL LLVM.
jlpeyton added a subscriber: openmp-commits.
AndreyChurbanov accepted this revision.Jul 7 2016, 11:26 AM
AndreyChurbanov edited edge metadata.

LGTM

This revision is now accepted and ready to land.Jul 7 2016, 11:26 AM
This revision was automatically updated to reflect the committed changes.