Yes, multithreaded guests are liable to crash; where they work they generally work more by luck than design. There is some discussion in LP:668799 of one of the known problems (whose symptoms are usually crashes or hangs).
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1098729 Title: qemu-user-static for armhf: segfault in threaded code Status in QEMU: New Bug description: Currently running QEMU from git (fedf2de31023) and running the armhf version of qemu-user-static which I have renamed qemu-armhf-static to follow the naming convention used in Debian. The host systems is a Debian testing x86_64-linux and I have an Debian testing armhf chroot which I invoke using schroot. Majority of program in the armhf chroot run fine, but I'm getting qemu segfaults in multi-threaded programs. As an example, I've grabbed the threads demo program here: https://computing.llnl.gov/tutorials/pthreads/samples/dotprod_mutex.c and changed NUMTHRDS from 4 to 10. I compile it as (same compile command on both x86_64 host and armhf guest): gcc -Wall -lpthread dotprod_mutex.c -o dotprod_mutex When compiled for x86_64 host it runs perfectly and even under Valgrind displays no errors whatsoever. However, when I compile the program in my armhs chroot and run it it usually (but not always) segaults or hangs or crashes. Example output: (armhf) $ ./dotprod_mutex Thread 1 did 100000 to 200000: mysum=100000.000000 global sum=100000.000000 Thread 0 did 0 to 100000: mysum=100000.000000 global sum=200000.000000 TCG temporary leak before f6731ca0 qemu-arm-static: /home/erikd/Git/qemu-posix-timer-hacking/Upstream/tcg/tcg-op.h:2371: tcg_gen_goto_tb: Assertion `(tcg_ctx.goto_tb_issue_mask & (1 << idx)) == 0' failed. (armhf) $ ./dotprod_mutex qemu: uncaught target signal 11 (Segmentation fault) - core dumped Segmentation fault (armhf) $ ./dotprod_mutex qemu-arm-static: /home/erikd/Git/qemu-posix-timer-hacking/Upstream/tcg/tcg.c:519: tcg_temp_free_internal: Assertion `idx >= s->nb_globals && idx < s->nb_temps' failed. (armhf) $ ./dotprod_mutex Thread 1 did 100000 to 200000: mysum=100000.000000 global sum=100000.000000 qemu: uncaught target signal 11 (Segmentation fault) - core dumped Segmentation fault To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1098729/+subscriptions
