I found last week that qemu-system-ppc64 (from git) hangs occasionally under load, and I have a reproducer for it now. Unfortunately the reproducer really takes a long time to run -- usually I can get a hang in under 12 hours.
Here is the reproducer case: https://lists.fedoraproject.org/pipermail/ppc/2012-June/001698.html Notes: (1) Verified by one other person (other than me). Happens on both ppc64 and x86-64 host. (2) Happens with both Fedora guest kernel 3.3.4-5.fc17.ppc64 and kernel 3.5.0 that I compiled myself. The test case above contains 3.3.4-5. (3) Seems to be a problem in qemu, not the guest. The reason I think this is because I tried to capture a backtrace of the hang using remote gdb, but gdb just hung when trying to connect to qemu (gdb connects fine before the bug happens). (4) Judging by guest messages, appears to be happening when writing to the disk. Reported: https://bugs.launchpad.net/qemu/+bug/1013241 Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones New in Fedora 11: Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 70 libraries supprt'd http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw
