Quoting Tamas Papp (1341...@bugs.launchpad.net): > On 07/16/2014 06:35 PM, Serge Hallyn wrote: > > > > To be clear, you have not yet gotten the bug since you've set > > KSM_ENABLED to 0, or have you? > > I just did it, so no, not yet. > > This happened by time: > > Saucy (everything is fine) -> Trusty (issue happened) -> Trusty with > Saucy kernel 3 weeks ago (no issue) -> today with 3 weeks uptime (issue > happened) -> KSM_ENABLED=0 + reboot with Trusty kernel -> now > > I just want to be clear, that both of us understand the same on this. > > > > Interesting about the saucy kernel. Ideally we could reproduce this > > reliably enough to really bisect. > > > > I wonder if we can reproduce without qemu. > > > I have a some other servers with LXC with no issue, If there is KVM, > then issue happens. > Does it really not show up anywhere else?
I've personally not seen it, and noone on my team, who use a lot of kvm instances, has seen it. Our two current theories are that (a) it has to do with ksm page migration across numa-nodes, or (b) it has to do with a race with transparent hugepages versus ksm. For (b) there is already a commit in Linus' tree (f72e7dcd). For (a), you can probably test by setting /sys/kernel/mm/ksm/merge_across_nodes to 0. (We are trying these as well, but as the testcases are not 100% positive it'd be good to have you try as well) -- 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/1341195 Title: KVM guests getting slow by time Status in “linux” package in Ubuntu: Incomplete Status in “qemu” package in Ubuntu: Incomplete Bug description: There is a post with very similar symptoms on serverfault: http://serverfault.com/questions/609881/windows-server-2012-on-kvm-on- ubuntu-14-04-runs-well-for-a-while-and-then-slows/612084#612084 Basically all kind of KVM guests are getting slow by time, both windows or linux. The more running guests, it happens sooner. Switching back to Saucy kernel is a good workaround. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: qemu-kvm 2.0.0+dfsg-2ubuntu1.1 ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2 Uname: Linux 3.13.0-29-generic x86_64 NonfreeKernelModules: zfs zunicode zavl zcommon znvpair ApportVersion: 2.14.1-0ubuntu3.2 Architecture: amd64 Date: Sat Jul 12 22:18:49 2014 SourcePackage: qemu UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1341195/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp