------- Comment From jhop...@us.ibm.com 2018-08-30 10:29 EDT------- Thanks, I've asked for some testing assistance from our KVM team but will note here some of the details from the original report of this problem..
repro steps are just a simple local host migration. ..they later noted that increasing the speed was a workaround: (qemu) migrate_set_speed 1G so you would want to test w/ default speed to confirm the issue is resolved (qemu) migrate -d tcp:localhost:4444 using " cosmic qemu version 1:2.12+dfsg-3 " from Bug 169712 / LP 1781526 (which enables qemu to use 2MB THP backing for powerpc), plus the test kernel build from this bug. Note without the kernel fix discussed in this bug, a migration problem might still happen even without that qemu THP patch if you got lucky enough to have a 2MB alignment by chance. ** Tags added: architecture-ppc64le bugnameltc-170805 severity-critical targetmilestone-inin--- -- 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/1788098 Title: Avoid migration issues with aligned 2MB THB Status in The Ubuntu-power-systems project: New Status in linux package in Ubuntu: In Progress Status in qemu package in Ubuntu: Invalid Status in linux source package in Bionic: In Progress Status in linux source package in Cosmic: In Progress Bug description: FYI: This blocks bug 1781526 - once this one here is resolved we can go on with SRU considerations for 1781526 ------- Comment From jhop...@us.ibm.com 2018-08-20 17:12 EDT------- Hi, in some environments it was observed that this qemu patch to enable THP made it more likely to hit guest migration issues, however the following kernel patch resolves those migration issues: https://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc.git/commit/?h=kvm-ppc-next&id=c066fafc595eef5ae3c83ae3a8305956b8c3ef15 KVM: PPC: Book3S HV: Use correct pagesize in kvm_unmap_radix() Once merged upstream, it would be good to include that change as well to avoid potential migration problems. Should I open a new bug for that or is it better to track here? Note Paelzer: I have not seen related migration issues myself, but it seems reasonable and confirmed by IBM. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1788098/+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
