------- Comment From marc.beye...@de.ibm.com 2019-01-17 09:26 EDT------- Hi there, here are the answers to your questions:
- Regarding gcc versions: We are using the standard gcc versions of the distros. This is gcc 5.4.0 on Ubuntu 16.04.5 LTS and 4.8.5 on the other distros. - Regarding kernel version: We are using 4.4 kernels on both distros. Current state of our analysis: - The problem is definitely SMT-2 related. In our current setup, all SPECint2017 micro-benchmarks are running with 2 instances each. If we run them with 1 instance each, the performance is almost identical to the other major Linux distros. - The problem is related to Position Independent Executables (PIEs). If we compile the SPECint2017 micro-benchmarks with "-no-pie", the performance on Ubuntu 16.04.5 LTS is almost identical to the other major Linux distros, also when running 2 instances for each micro-benchmark. - We suspected Kernel commit a73dc5370e153ac63718d850bddf0c9aa9d871e6 to be the culprit, since this commit is related to PIEs and has been reverted by commit 345f8f34bb473241d62803951c18a844dd705f8d at a later point in time. However, newly executed test runs revealed that this commit is not causing the observed performance degradation. - We are continuing our analysis :-) Stay tuned. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1812182 Title: Performance degradation with SPECint2017 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1812182/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
