Quoting Tamas Papp ([email protected]): > 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 Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1341195 Title: KVM guests getting slow by time To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1341195/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
