Hi Thomas, Thank you for looking into this!
On 06/03/2026 10:57, Thomas Gleixner wrote: > On Fri, Mar 06 2026 at 06:48, Jiri Slaby wrote: >> On 05. 03. 26, 20:25, Thomas Gleixner wrote: >>> Is there simple way to reproduce? >> >> Unfortunately not at all. To date, I even cannot reproduce locally, it >> reproduces exclusively in opensuse build service (and github CI as per >> Matthieu's report). I have a project in there with packages which fail >> more often than others: >> https://build.opensuse.org/project/monitor/home:jirislaby:softlockup >> But it's all green ATM. >> >> Builds of Go 1.24 and tests of rust 1.90 fail the most. The former even >> takes only ~ 8 minutes, so it's not that intensive build at all. So the >> reasons are unknown to me. At least, Go apparently uses threads for >> building (unlike gcc/clang with forks/processes). Dunno about rust. > > I tried with tons of test cases which stress test mmcid with threads and > failed. On my side, I didn't manage to reproduce it locally either. > Can you provide me your .config, source version, VM setup (Number of > CPUs, memory etc.)? My CI ran into this issue 2 days ago, with and without a debug kernel config. The kernel being tested was on top of 'net-next', which was on top of this commit from Linus' tree: fbdfa8da05b6 ("selftests: tc-testing: fix list_categories() crash on list type"). - Config without debug: https://github.com/user-attachments/files/25791728/config-run-22657946888-normal-join.gz - Config with debug: https://github.com/user-attachments/files/25791960/config-run-22657946888-debug-nojoin.gz - Just in case, stacktraces available there: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/22657946888 My tests are being executed in VMs I don't control using a kernel v6.14 on Azure with 4 vCPUs, 16GB of RAM, and KVM nested support. From more details about what's in it: https://github.com/actions/runner-images/blob/ubuntu24/20260302.42/images/ubuntu/Ubuntu2404-Readme.md >From there, a docker container is started, from which QEMU 10.1.0 (Debian 1:10.1.0+ds-5ubuntu2.2) is launched with 4 vCPU and 5GB of RAM using this command: /usr/bin/qemu-system-x86_64 \ -name mptcpdev \ -m 5120M \ -smp 4 \ -chardev socket,id=charvirtfs5,path=/tmp/virtmevrwrzu5k \ -device vhost-user-fs-device,chardev=charvirtfs5,tag=ROOTFS \ -object memory-backend-memfd,id=mem,size=5120M,share=on \ -numa node,memdev=mem \ -machine accel=kvm:tcg \ -M microvm,accel=kvm,pcie=on,rtc=on \ -cpu host,topoext=on \ -parallel none \ -net none \ -echr 1 \ -chardev file,path=/proc/self/fd/2,id=dmesg \ -device virtio-serial-device \ -device virtconsole,chardev=dmesg \ -chardev stdio,id=console,signal=off,mux=on \ -serial chardev:console \ -mon chardev=console \ -vga none \ -display none \ -device vhost-vsock-device,guest-cid=3 \ -kernel /home/runner/work/mptcp_net-next/mptcp_net-next/.virtme/build/arch/x86/boot/bzImage \ -append 'virtme_hostname=mptcpdev nr_open=1048576 virtme_link_mods=/home/runner/work/mptcp_net-next/mptcp_net-next/.virtme/build/.virtme_mods/lib/modules/0.0.0 virtme_rw_overlay0=/tmp console=hvc0 earlyprintk=serial,ttyS0,115200 virtme_console=ttyS0 psmouse.proto=exps virtme.vsockexec=`/tmp/virtme-console/3.sh` virtme_chdir=home/runner/work/mptcp_net-next/mptcp_net-next virtme_root_user=1 rootfstype=virtiofs root=ROOTFS raid=noautodetect rw debug nokaslr mitigations=off softlockup_panic=1 nmi_watchdog=1 hung_task_panic=1 panic=-1 oops=panic init=/usr/local/lib/python3.13/dist-packages/virtme/guest/bin/virtme-ng-init' \ -gdb tcp::1234 \ -qmp tcp::3636,server,nowait \ -no-reboot It is possible to locally launch the same command using the same QEMU version (but not the same host kernel) with the help of Docker: $ cd <kernel source code> # docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --rm \ -it --privileged mptcp/mptcp-upstream-virtme-docker:latest \ manual normal This will build a new kernel in O=.virtme/build, launch it and give you access to a prompt. After that, you can do also use the "auto" mode with the last built image to boot the VM, only print "OK", stop and retry if there were no errors: $ cd <kernel source code> $ echo 'echo OK' > .virtme-exec-run # i=1; \ while docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --rm \ -it --privileged mptcp/mptcp-upstream-virtme-docker:latest \ vm auto normal; do \ echo "== Attempt: $i: OK =="; \ i=$((i+1)); \ done; \ echo "== Failure after $i attempts ==" > I tried to find it on that github page Matthiue mentioned but I'm > probably too stupid to navigate this clicky interface. I'm sorry about that, I understand, the interface is not very clear. Do not hesitate to tell me if you need anything else from me. Cheers, Matt -- Sponsored by the NGI0 Core fund.
