** Description changed: [Impact] The LTP cpuset_sched_domains test, authored by Miao Xie, fails on a Kunpeng920 server that has 4 NUMA nodes: - https://launchpad.net/bugs/1951289 + https://launchpad.net/bugs/1951289 This does appear to be a real bug. /proc/schedstat displays 4 domain levels for CPUs on 2 of the nodes, but only 3 levels for the others 2 (see below). I assume this means the scheduler is making suboptimal decisions about where to place/move processes. [Test Case] On a 128 core Kunpeng 920 system, observe that half the CPUs are missing a 3rd level scheduling domain: ubuntu@d06-4:~$ grep domain2 /proc/schedstat | wc -l 128 ubuntu@d06-4:~$ grep domain3 /proc/schedstat | wc -l 64 - ubuntu@d06-4:~$ + ubuntu@d06-4:~$ [What Could Go Wrong] - This changes the code used for populating sched domains, so it could potentially break on other systems, potentially leading to poor scheduling characteristics (higher latencies, lower overall throughput etc). + This changes the code used for populating sched domains, so it could potentially break on other systems, leading to poor scheduling characteristics (higher latencies, lower overall throughput etc).
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1951289 Title: ubuntu_ltp_controllers:cpuset_sched_domains: tests 3,9,11,17,19,25 report incorrect sched domain for cpu#32 To manage notifications about this bug go to: https://bugs.launchpad.net/kunpeng920/+bug/1951289/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
