hello, i have found that there is an old bug still around in linux, which is causing quite an amount of unnecessary cpu consumption in kvm/proxmox, and thus, wasting precious power.
i run some proxmox installations on older systems and on those, it's quite significant difference. on the slowest system, a single debian 10 VM , kvm process is at 20% cpu (VM is 100% idle) when this issue is present. if i change VMs machine type from i440fx(default) to q35 the problem goes away. the same applies when running "powertop --auto-tune" inside the guest (with i440fx type - enable autosuspend for usb-controller + tablet device). on some L5630 machine, in proxmox summary i see "CPU usage" drop from 10% to <1%. see: https://bugzilla.redhat.com/show_bug.cgi?id=478317 https://bugzilla.redhat.com/show_bug.cgi?id=949547 i guess this information could make a difference for people who run a large amount of virtual machines or use older systems/cpu's. on most recent cpu's, i think the difference is not that big. anyway, i really wonder how linux bugs have such great survival capability.... regards roland more references: https://lists.gnu.org/archive/html/qemu-devel/2010-04/msg00149.html https://www.redhat.com/archives/vfio-users/2015-November/msg00159.html _______________________________________________ pve-user mailing list [email protected] https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-user
