Hi Ethanay > All I can find is a recommendation not to use it on CPUs with 2 or fewer > cores as the overhead is said to be too high
This isn't a real problem anyway, the service will stop immediately if only running on one core - even if running on multiple cores with the same cache (as the intended benefit is due to cache hotness by having all I/O hitting the same cache). > I can imagine it might still add undesirable or even critical latency in > applications that are highly latency sensitive I understand your line of thought, but it might even improve latency. If there is no bottleneck on the cores assigned to handle an IRQ then the improved cache hit rate will make even latency better. And if there is a strong bottleneck, then some drivers without IRQbalance would end up locked on one cpu - so again these might gain lower latency. But I have no data on this either (just like no one seems to have on almost any of this). Just like others I'd personally more expect the drawback to be on a potential lack of power saving. > This website gave me some clarity on the theory and purpose: > https://www.baeldung.com/linux/irqbalance-modern-hardware Hah, didn't find this one yet - thank you! But to me it only underlines the "it can help as much or even more often" expectation. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ubuntu-meta in Ubuntu. https://bugs.launchpad.net/bugs/1833322 Title: Consider removing irqbalance from default install on desktop images Status in irqbalance package in Ubuntu: Confirmed Status in ubuntu-meta package in Ubuntu: Confirmed Bug description: as per https://github.com/pop-os/default-settings/issues/60 Distribution (run cat /etc/os-release): $ cat /etc/os-release NAME="Pop!_OS" VERSION="19.04" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Pop!_OS 19.04" VERSION_ID="19.04" HOME_URL="https://system76.com/pop"; SUPPORT_URL="http://support.system76.com"; BUG_REPORT_URL="https://github.com/pop-os/pop/issues"; PRIVACY_POLICY_URL="https://system76.com/privacy"; VERSION_CODENAME=disco UBUNTU_CODENAME=disco Related Application and/or Package Version (run apt policy $PACKAGE NAME): $ apt policy irqbalance irqbalance: Installed: 1.5.0-3ubuntu1 Candidate: 1.5.0-3ubuntu1 Version table: *** 1.5.0-3ubuntu1 500 500 http://us.archive.ubuntu.com/ubuntu disco/main amd64 Packages 100 /var/lib/dpkg/status $ apt rdepends irqbalance irqbalance Reverse Depends: Recommends: ubuntu-standard gce-compute-image-packages Issue/Bug Description: as per konkor/cpufreq#48 and http://konkor.github.io/cpufreq/faq/#irqbalance-detected irqbalance is technically not needed on desktop systems (supposedly it is mainly for servers), and may actually reduce performance and power savings. It appears to provide benefits only to server environments that have relatively-constant loading. If it is truly a server- oriented package, then it shouldn't be installed by default on a desktop/laptop system and shouldn't be included in desktop OS images. Steps to reproduce (if you know): This is potentially an issue with all default installs. Expected behavior: n/a Other Notes: I can safely remove it via "sudo apt purge irqbalance" without any apparent adverse side-effects. If someone is running a situation where they need it, then they always have the option of installing it from the repositories. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/irqbalance/+bug/1833322/+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
