@rbalint if you can reproduce the problem easily, it would be interesting to monitor the received ACPI events via acpi_listen.
What I see during my tests is that acpi_listen is always showing the sleep events, meaning that the kernel receives them correctly at least, and then the failure happens in the delivery of these sleep events to the proper user-space daemon (acpid). So my guess is that something wrong is happening in the communication between kernel and user-space to deliver these events. Just to make sure, when you say "the second hibernation attempt still fails" you mean that the system is still up & running (you can still ssh on it) and the sleep event is lost / not delivered properly, right? -- 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/1864045 Title: [SRU] Hibernation events sometimes missed on repeated attempts Status in acpid package in Ubuntu: Confirmed Status in linux package in Ubuntu: Incomplete Status in acpid source package in Bionic: Incomplete Status in linux source package in Bionic: Incomplete Status in acpid source package in Eoan: Confirmed Status in linux source package in Eoan: Incomplete Bug description: When testing hibernation / resume on AWS with 5.0 or 5.3 kernels on bionic (using acpid 1:2.0.28-1ubuntu1), we sometimes see failure with repeated attempts. The first attempt will always be triggered, but the next attempt may not. The result is the agent never triggers the hibernation process and the instance will be forced to shutdown after a timeout period. Two workarounds have been identified. The first is to restart acpid during the resume handler. The second is to use the latest upstream acpid (as of Feb 1, 2020). This second workaround indicates there may be a patch missing in the acpid in bionic (1:2.0.28-1ubuntu1) to work with the 5.0+ kernels. To reproduce this problem: 1) Launch an c4, c5, m4, m5, r4, r5 instance type with a 5.0 or 5.3 kernel on a bionic image with on-demand hibernation support enabled. 2) Hibernate and resume the instance, ensuring the system is fully resumed afterward and the swap file has been removed. 3) Hibernate and resume another time. The hibernate should be triggered immediately and the instance should become unresponsive as it saves state to disk. 4) Resume the instance, it should come back with the same processes running. 5) Repeat 3) - 4) as necessary. --- ProblemType: Bug ApportVersion: 2.20.9-0ubuntu7.9 Architecture: amd64 DistroRelease: Ubuntu 18.04 Ec2AMI: ami-0edf3b95e26a682df Ec2AMIManifest: (unknown) Ec2AvailabilityZone: us-west-2a Ec2InstanceType: m4.large Ec2Kernel: unavailable Ec2Ramdisk: unavailable Package: acpid 1:2.0.28-1ubuntu1 PackageArchitecture: amd64 ProcEnviron: TERM=screen PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=C.UTF-8 SHELL=/bin/bash ProcVersionSignature: User Name 5.0.0-1025.28-aws 5.0.21 Tags: bionic ec2-images Uname: Linux 5.0.0-1025-aws x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm audio cdrom dialout dip floppy lxd netdev plugdev sudo video _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/acpid/+bug/1864045/+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