Joe - thanks for the test kernel. Patches submitted: https://lists.ubuntu.com/archives/kernel- team/2016-June/077944.html
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-lts-utopic in Ubuntu. https://bugs.launchpad.net/bugs/1587087 Title: OOM in guest Ubuntu with inflated balloon Status in linux-lts-utopic package in Ubuntu: In Progress Status in linux-lts-utopic source package in Trusty: In Progress Bug description: There is QEMU/KVM and a Linux OS running inside the guest. Inside the Linux guest a balloon consumes memory in accordance with commands performed on the host side in QEMU. Rapid increases of memory consumption inside the guest may end up with guest OOMs since memory locked by balloon couldn’t be returned to the guest OS/vm in time. The problem is addressed in mainstream Linux with the following patchset: commit 5a10b7dbf904bfe01bb9fcc6298f7df09eed77d5 Author: Raushaniya Maksudova <rmaksud...@parallels.com> Date: Mon Nov 10 09:36:29 2014 +1030 virtio_balloon: free some memory from balloon on OOM Excessive virtio_balloon inflation can cause invocation of OOM-killer, when Linux is under severe memory pressure. Various mechanisms are responsible for correct virtio_balloon memory management. Nevertheless it is often the case that these control tools does not have enough time to react on fast changing memory load. As a result OS runs out of memory and invokes OOM-killer. The balancing of memory by use of the virtio balloon should not cause the termination of processes while there are pages in the balloon. Now there is no way for virtio balloon driver to free some memory at the last moment before some process will be get killed by OOM-killer. This does not provide a security breach as balloon itself is running inside guest OS and is working in the cooperation with the host. Thus some improvements from guest side should be considered as normal. To solve the problem, introduce a virtio_balloon callback which is expected to be called from the oom notifier call chain in out_of_memory() function. If virtio balloon could release some memory, it will make the system to return and retry the allocation that forced the out of memory killer to run. Allocate virtio feature bit for this: it is not set by default, the the guest will not deflate virtio balloon on OOM without explicit permission from host. Signed-off-by: Raushaniya Maksudova <rmaksud...@parallels.com> Signed-off-by: Denis V. Lunev <d...@openvz.org> Acked-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au> commit 1fd9c67203af91977bf3b964ff3744cf74fc6f3f Author: Raushaniya Maksudova <rmaksud...@parallels.com> Date: Mon Nov 10 09:35:29 2014 +1030 virtio_balloon: return the amount of freed memory from leak_balloon() This value would be useful in the next patch to provide the amount of the freed memory for OOM killer. Signed-off-by: Raushaniya Maksudova <rmaksud...@parallels.com> Signed-off-by: Denis V. Lunev <d...@openvz.org> CC: Rusty Russell <ru...@rustcorp.com.au> CC: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au> The problem is present in Ubuntu 14.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-utopic/+bug/1587087/+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