Hi David, On 2024-05-23 08:44, David Howells wrote: > In https://bugs.launchpad.net/ubuntu/+source/autopkgtest/+bug/2056461 you say: > > | It seems that kernel 6.8 introduced a regression in the 9pfs related to > | caching and netfslib, that can cause some user-space apps to read content > | from files that is not up-to-date (when they are used in a producer/consumer > | fashion). > > Can you clarify how these files are being used? I don't know the details of the 9pfs operations involved, but still I wanted to mention that to reliably reproduce the issue on a Debian system one can run: autopkgtest-build-qemu unstable /tmp/sid.img autopkgtest -ddd -B dpdk -- autopkgtest-virt-qemu --debug --show-boot /tmp/sid.img If the kernel installed in the guest VM is affected by this problem, after a while the test hangs with something like: autopkgtest-virt-qemu: DBG: executing copydown /tmp/alog/tests-tree/ /tmp/autopkgtest.uG6tsJ/build.6QA/src/ [...] autopkgtest-virt-qemu: DBG: +>? Full logs at https://people.debian.org/~ema/1072004-6.10-rc1.log Part of the code mounting the 9pfs in case it helps is at: https://salsa.debian.org/ci-team/autopkgtest/-/blob/master/virt/autopkgtest-virt-qemu#L290 I could reproduce the issue with both 6.9.2 and 6.10-rc1.