Public bug reported: linux 3.13.0-24.46
transparent hugepages, which are configured on by default in Ubuntu, are flaky on arm64. The most evident system is that go processes reliably hang or crash. This has been observed with both building juju-core with gccgo, and running the resulting juju binaries. The root cause of this is that get_user_pages_fast is not yet implemented on arm64 (and arm64). Patches are floating around, but haven't landed. http://comments.gmane.org/gmane.linux.ports.arm.kernel/299268 We've verified that either applying those patches, or disabling THP via sysfs, prevents the above issues. At minimum we should change the default boottime sysfs setting for THP to "never" until we can fix this feature properly. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- 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/1309221 Title: transparent hugepages flaky on arm64 Status in “linux” package in Ubuntu: New Bug description: linux 3.13.0-24.46 transparent hugepages, which are configured on by default in Ubuntu, are flaky on arm64. The most evident system is that go processes reliably hang or crash. This has been observed with both building juju-core with gccgo, and running the resulting juju binaries. The root cause of this is that get_user_pages_fast is not yet implemented on arm64 (and arm64). Patches are floating around, but haven't landed. http://comments.gmane.org/gmane.linux.ports.arm.kernel/299268 We've verified that either applying those patches, or disabling THP via sysfs, prevents the above issues. At minimum we should change the default boottime sysfs setting for THP to "never" until we can fix this feature properly. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1309221/+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
