Public bug reported: Using the code from https://github.com/JasonGross/csdp-test (also attached), on my 12-core machine, I get a massive slowdown between using 1 core, and using 3 cores; the relevant snippet from the output of `make` in that repo is:
Testing on up to 12 cores 0 (real: 0.00, user: 0.00, sys: 0.00, mem: 3660 ko) 1 (real: 1.57, user: 1.56, sys: 0.00, mem: 3668 ko) 2 (real: 1.57, user: 3.10, sys: 0.01, mem: 3648 ko) 3 (real: 1.61, user: 3.17, sys: 0.01, mem: 3664 ko) 4 (real: 1.63, user: 4.78, sys: 0.00, mem: 3660 ko) 5 (real: 1.68, user: 6.44, sys: 0.00, mem: 3696 ko) 6 (real: 1.84, user: 8.60, sys: 0.00, mem: 3708 ko) 7 (real: 1.85, user: 8.82, sys: 0.01, mem: 3720 ko) 8 (real: 2.14, user: 12.07, sys: 0.02, mem: 3712 ko) 9 (real: 2.22, user: 12.59, sys: 0.01, mem: 3736 ko) 10 (real: 2.25, user: 14.65, sys: 0.01, mem: 3764 ko) 11 (real: 2.35, user: 16.65, sys: 0.13, mem: 3720 ko) 1) $ lsb_release -rd Description: Ubuntu 14.04.3 LTS Release: 14.04 2) $ apt-cache policy coinor-csdp coinor-csdp: Installed: 6.1.1-1 Candidate: 6.1.1-1 Version table: *** 6.1.1-1 0 500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages 100 /var/lib/dpkg/status 3) What you expected to happen 12 cores should be no slower than 1 core 4) What happened instead 12 cores is about 1000x slower than 1 core Note: Test cases from https://coq.inria.fr/bugs/show_bug.cgi?id=4983#c9 ** Affects: coinor-csdp (Ubuntu) Importance: Undecided Status: New ** Attachment added: "testing code" https://bugs.launchpad.net/bugs/1619055/+attachment/4731822/+files/csdp-test-master.zip -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1619055 Title: csdp duration grows with the number of cores available (12 is about 1000x slower than 1) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/coinor-csdp/+bug/1619055/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs