[Bug 1368439] Re: Random high latency with KSM enabled and multiple CPU sockets
[Expired for qemu-kvm (Ubuntu) because there has been no activity for 60 days.] ** Changed in: qemu-kvm (Ubuntu) Status: Incomplete = Expired -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/1368439 Title: Random high latency with KSM enabled and multiple CPU sockets To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1368439/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1368439] Re: Random high latency with KSM enabled and multiple CPU sockets
[Expired for linux (Ubuntu) because there has been no activity for 60 days.] ** Changed in: linux (Ubuntu) Status: Incomplete = Expired -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/1368439 Title: Random high latency with KSM enabled and multiple CPU sockets To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1368439/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1368439] Re: Random high latency with KSM enabled and multiple CPU sockets
Is this still an issue for you? There were some actual KSM corruption bugs which were somewhat recently fixed. KSM in general wil use more CPU in order to reduce memory contention, so your results are not necessarily unexpected. Aside from turning KSM off, you can also reduce the KSM frequency. There are some other tuning hints at http://www.linux- kvm.org/page/Tuning_Kernel ** Changed in: qemu-kvm (Ubuntu) Status: New = Incomplete ** Changed in: qemu-kvm (Ubuntu) Importance: Undecided = Low -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/1368439 Title: Random high latency with KSM enabled and multiple CPU sockets To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1368439/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1368439] Re: Random high latency with KSM enabled and multiple CPU sockets
I should add that to fix this while running you need to do, as root: echo 2 /sys/kernel/mm/ksm/run This makes the pages duplicate, might take a second or two and disables KSM. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/1368439 Title: Random high latency with KSM enabled and multiple CPU sockets To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1368439/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1368439] Re: Random high latency with KSM enabled and multiple CPU sockets
** Also affects: linux (Ubuntu) Importance: Undecided Status: New ** No longer affects: linux -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/1368439 Title: Random high latency with KSM enabled and multiple CPU sockets To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1368439/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1368439] Re: Random high latency with KSM enabled and multiple CPU sockets
I've looked through all the logs that are relevant and can't find any specific output that's relevant - marking as confirmed. If you've got any logs in specific you need me to pull out I can do so. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/1368439 Title: Random high latency with KSM enabled and multiple CPU sockets To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1368439/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1368439] Re: Random high latency with KSM enabled and multiple CPU sockets
Wait, someone else needs to mark it as confirmed. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/1368439 Title: Random high latency with KSM enabled and multiple CPU sockets To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1368439/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
