On the previously mentioned HP server today I was able to get closer to reproducing the situation by testing with bionic (4.15.0-47-generic) instead of xenial (4.4)
On bionic, unlike xenial, even with the BIOS set to "BIOS controlled dynamic" mode, the intel_pstate driver is loaded instead of pcc-cpufreq Found this kernel commit: https://github.com/torvalds/linux/commit/bfa54a3a00e2f7ff051a50f3957e4fca3d73f6e7 Pull power management fix from Rafael Wysocki: "Fix a relatively old initialization issue in intel_pstate causing the pcc-cpufreq driver to be used instead of it on some HP Proliant systems. This turned into a functional regression during the 4.17 cycle, because pcc-cpufreq is a scalability disaster and that was amplified by the idle loop rework done at that time (Rafael Wysocki). This suggests there has definitely been some related change in this area that sound very much similar to this which is worth further research. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1806012 Title: set-cpufreq: 'powersave' governor configuration sanity on ubuntu server Status in systemd package in Ubuntu: In Progress Status in systemd source package in Xenial: In Progress Status in systemd source package in Bionic: In Progress Status in systemd source package in Cosmic: In Progress Status in systemd source package in Disco: In Progress Bug description: Whilst debugging 'slow instance performance' on a Ubuntu Bionic based cloud, I observed that the default cpu governor configuration was set to 'powersave'; toggling this to 'performance' (while in not anyway a particularly green thing todo) resulted in the instance slowness disappearing and the cloud performance being as expected (based on a prior version of the deploy on Ubuntu Xenial). AFAICT Xenial does the same thing albeit in a slight different way, but we definitely did not see the same performance laggy-ness under a Xenial based cloud. Raising against systemd (as this package sets the governor to 'powersave') - I feel that the switch to 'performance' although appropriate then obscures what might be a performance/behavioural difference in the underlying kernel when a machine is under load. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: systemd 237-3ubuntu10.9 ProcVersionSignature: Ubuntu 4.15.0-39.42-generic 4.15.18 Uname: Linux 4.15.0-39-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.5 Architecture: amd64 Date: Fri Nov 30 10:05:46 2018 Lsusb: Bus 002 Device 002: ID 8087:8002 Intel Corp. Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 003: ID 413c:a001 Dell Computer Corp. Hub Bus 001 Device 002: ID 8087:800a Intel Corp. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: Dell Inc. PowerEdge R630 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=C.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-39-generic root=UUID=a361a524-47eb-46c3-8a04-e5eaa65188c9 ro hugepages=103117 iommu=pt intel_iommu=on SourcePackage: systemd UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 11/08/2016 dmi.bios.vendor: Dell Inc. dmi.bios.version: 2.3.4 dmi.board.name: 02C2CP dmi.board.vendor: Dell Inc. dmi.board.version: A03 dmi.chassis.type: 23 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr2.3.4:bd11/08/2016:svnDellInc.:pnPowerEdgeR630:pvr:rvnDellInc.:rn02C2CP:rvrA03:cvnDellInc.:ct23:cvr: dmi.product.name: PowerEdge R630 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1806012/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
