cc: qemu-devel Hi, I'm trying to help progress a very troublesome and so far elusive bug we're seeing in Fedora infrastructure. When running dozens of qemu-kvm VMs simultaneously, eventually they become unresponsive, as well as new processes as we try to extract information from the host about what's gone wrong. Systems (Fedora openQA worker hosts) on kernel 5.12.12+ wind up in a state where forking does not work correctly, breaking most things https://bugzilla.redhat.com/show_bug.cgi?id=2009585 In subsequent testing, we used newer kernels with lockdep and other debug stuff enabled, and managed to capture a hung task with a bunch of locks listed, including kvm and qemu processes. But I can't parse it. 5.15-rc7 https://bugzilla-attachments.redhat.com/attachment.cgi?id=1840941 5.15+ https://bugzilla-attachments.redhat.com/attachment.cgi?id=1840939 If anyone can take a glance at those kernel messages, and/or give hints how we can extract more information for debugging, it'd be appreciated. Maybe all of that is normal and the actual problem isn't in any of these traces. Thanks, -- Chris Murphy
