------- Comment From leona...@ibm.com 2019-02-25 18:35 EDT------- I cherry-picked all patches on top of ubuntu-bionic (Ubuntu-4.15.0-45.48).
Then, the next step was trying to find a way to reproduce the bug. I have noted, after several tests, that the previous suggestion of Michael Ranweiler was valid, but it's reproduction rate is about 50%. As previously I have tested only a few times, I could not get it to reproduce. How it fails: During 'memtest' second part, on a 'migrated to' guest, one of the migrations (that occur in parallel) would exit with a "Segmentation Fault" and not conclude the normal flow of the test. (It never reaches the puts part) After applying the kernel patches, it seems to work just fine all the times (I have tested 10+ times by now). The kernel debs generated by the building process can be downloaded on the link bellow: ftp://testcase.software.ibm.com/fromibm/linux/patched_kernel.tar.gz - Please use user=anonymous, passwd=anonymous if asked - Make sure to download it soon, as the link will be available for 3 business days. Building info: command: fakeroot debian/rules binary-generic binary-perarch git repo (before patches) : git://kernel.ubuntu.com/ubuntu/ubuntu-bionic.git (tag: Ubuntu-4.15.0-45.48) -- 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: Invalid Status in linux package in Ubuntu: Invalid Status in qemu package in Ubuntu: Invalid Status in linux source package in Bionic: Invalid Status in linux source package in Cosmic: Invalid 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
