A v9 was posted on August 31st, but there is still no progress upstream. Meanwhile, Peter Zijlstra merged 0d3d73aac2ff05c78387aa9dcc2c8aa3804405e7 ("perf/core: Rewrite event timekeeping"), which looks like would have helped with this problem.
Can you confirm if the latest bionic kernel, which has this commit, scales better? If not, what is the plan of pushing this forward upstream? Cascardo. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1730782 Title: [Bug] [KNL] ~5x slowdown of application when attaching by perf on KNL Status in intel: New Status in linux package in Ubuntu: Triaged Status in linux source package in Bionic: Triaged Bug description: Description: Workload slows down for default sampling cycles in KNL. There are some processing in perf that's single threaded and bottlenecked when number of cores really go up. A second issue is that things slow down when we issue perf record – workload vs perf record -a – workload Patch is submitted for review https://www.spinics.net/lists/kernel/msg2552460.html https://www.spinics.net/lists/kernel/msg2552461.html https://www.spinics.net/lists/kernel/msg2552462.html https://www.spinics.net/lists/kernel/msg2552463.html Target kernel: TBD Target Release: 18.04 To manage notifications about this bug go to: https://bugs.launchpad.net/intel/+bug/1730782/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : email@example.com Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp