Could not reproduce with reproducer on Xenial, with lxcfs 2.0.8-0ubuntu1~16.04.2 running on the GA 4.4 and HWE 4.15 kernels. Xenial does not appear to be affected.
** Changed in: lxcfs (Ubuntu Xenial) Status: New => Invalid ** Changed in: lxcfs (Ubuntu Eoan) Status: New => In Progress ** Changed in: lxcfs (Ubuntu Eoan) Importance: Undecided => Medium ** Changed in: lxcfs (Ubuntu Eoan) Assignee: (unassigned) => Kellen Renshaw (krenshaw) -- You received this bug notification because you are a member of नेपाली भाषा समायोजकहरुको समूह, which is subscribed to Xenial. Matching subscriptions: Ubuntu 16.04 Bugs https://bugs.launchpad.net/bugs/1860813 Title: LXC container reports spike in swap occasionally Status in lxcfs package in Ubuntu: Fix Released Status in lxcfs source package in Xenial: Invalid Status in lxcfs source package in Bionic: In Progress Status in lxcfs source package in Eoan: In Progress Bug description: [Impact] * lxcfs provides a container-specific view of /proc/meminfo. Occasionally, with near zero or zero swap usage *and* swap accounting turned on (kernel parameter swapaccount=1), the container will report 100% swap utilization. * This issue has been encountered and could result in unecessary alerts or potential automated attempts at remediating a non-existent "full swap" issue. * This fix changed the logic used for SwapFree when swap accounting is enabled to better handle situations where memswusage is less than memusage, caused by the fuzziness of the usage_in_bytes counters used as the source. Specifically, it added a check for memusage being larger than memswusage and if so, sets 0 as the value of swapusage. Otherwise the calculation (memswusage - memusage) remains the same. [Test Case] * Requires a Bionic (18.04) or Eoan (19.10) host with swap space. * Enable swap accounting with the "swapaccount=1" kernel parameter on the kernel command line. Edit /etc/default/grub, add "swapaccount=1" to the GRUB_CMDLINE_LINUX_DEFAULT="other parameters" line, then run "update-grub" and reboot to make the change active. * Ensure lxd is installed, "sudo apt install lxd" * Create a lxd/lxc container with "lxc launch ubuntu:X container_name" with X being either b[ionic] or e[oan]. * Open two shells to the container with "lxc shell container_name" * In one of the shells, run: watch -n 0.1 "grep Swap /proc/meminfo" * In the other, run: while true; do free; done * You should see SwapFree intermittently drop to zero in the first terminal. * The fix results in small non-zero swap "usage" intermittently instead of intermittent SwapFree = 0. [Regression Potential] * Low, as swap accounting must be enabled to encounter the bug and the fix. * Potential for unanticipated edge cases in the values of memusage and memswusage to cause incorrect swap reporting within the container, with swap accounting turned on. * Any tooling that expected, compensated, or relied on the behavior may no longer work as expected. [Other Info] * Cherrypick of a one line fix to address this specific situation. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lxcfs/+bug/1860813/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~group.of.nepali.translators Post to : group.of.nepali.translators@lists.launchpad.net Unsubscribe : https://launchpad.net/~group.of.nepali.translators More help : https://help.launchpad.net/ListHelp