Re: [Qemu-devel] [PATCH 0/4] Tweaks around virtio-blk start/stop

[Christian Borntraeger]

Good (or bad?) news is the assert also triggers on F23, it just seems to take 
longer.

trace 1 (compiled on F20)

Thread 5 (Thread 0x3ff84b7f910 (LWP 33030)):
#0  0x000003ff86a817b8 in ppoll () at /lib64/libc.so.6
#1  0x00000000102c712e in qemu_poll_ns (fds=0x3ff80001e70, nfds=3, timeout=-1) 
at /home/cborntra/REPOS/qemu/qemu-timer.c:313
#2  0x00000000102c96d6 in aio_poll (ctx=0x10a7b050, blocking=true) at 
/home/cborntra/REPOS/qemu/aio-posix.c:453
#3  0x000000001014fb1e in iothread_run (opaque=0x10a7ab10) at 
/home/cborntra/REPOS/qemu/iothread.c:46
#4  0x000003ff86b87c2c in start_thread () at /lib64/libpthread.so.0
#5  0x000003ff86a8ec9a in thread_start () at /lib64/libc.so.6

Thread 4 (Thread 0x3ff8537f910 (LWP 33029)):
#0  0x000003ff86a8841e in syscall () at /lib64/libc.so.6
#1  0x000000001039cbe8 in futex_wait (ev=0x10a140ec <rcu_call_ready_event>, 
val=4294967295) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:292
#2  0x000000001039ce1e in qemu_event_wait (ev=0x10a140ec 
<rcu_call_ready_event>) at 
/home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:399
#3  0x00000000103b9678 in call_rcu_thread (opaque=0x0) at 
/home/cborntra/REPOS/qemu/util/rcu.c:250
#4  0x000003ff86b87c2c in start_thread () at /lib64/libpthread.so.0
#5  0x000003ff86a8ec9a in thread_start () at /lib64/libc.so.6

Thread 3 (Thread 0x3ff66428910 (LWP 33041)):
#0  0x000003ff86a8334a in ioctl () at /lib64/libc.so.6
#1  0x000000001007b97a in kvm_vcpu_ioctl (cpu=0x10b15970, type=44672) at 
/home/cborntra/REPOS/qemu/kvm-all.c:1984
#2  0x000000001007b2f0 in kvm_cpu_exec (cpu=0x10b15970) at 
/home/cborntra/REPOS/qemu/kvm-all.c:1834
#3  0x000000001005bd92 in qemu_kvm_cpu_thread_fn (arg=0x10b15970) at 
/home/cborntra/REPOS/qemu/cpus.c:1050
#4  0x000003ff86b87c2c in start_thread () at /lib64/libpthread.so.0
#5  0x000003ff86a8ec9a in thread_start () at /lib64/libc.so.6

Thread 2 (Thread 0x3ff885dbb90 (LWP 32970)):
#0  0x000003ff86a817b8 in ppoll () at /lib64/libc.so.6
#1  0x00000000102c7244 in qemu_poll_ns (fds=0x10a77a90, nfds=5, 
timeout=965000000) at /home/cborntra/REPOS/qemu/qemu-timer.c:325
#2  0x00000000102c5ef2 in os_host_main_loop_wait (timeout=965000000) at 
/home/cborntra/REPOS/qemu/main-loop.c:251
#3  0x00000000102c6006 in main_loop_wait (nonblocking=0) at 
/home/cborntra/REPOS/qemu/main-loop.c:505
#4  0x00000000101667e4 in main_loop () at /home/cborntra/REPOS/qemu/vl.c:1933
#5  0x000000001016e8ea in main (argc=72, argv=0x3ffe977e978, 
envp=0x3ffe977ebc0) at /home/cborntra/REPOS/qemu/vl.c:4656

Thread 1 (Thread 0x3ff66c28910 (LWP 33033)):
#0  0x000003ff869be2c0 in raise () at /lib64/libc.so.6
#1  0x000003ff869bfc26 in abort () at /lib64/libc.so.6
#2  0x000003ff869b5bce in __assert_fail_base () at /lib64/libc.so.6
#3  0x000003ff869b5c5c in  () at /lib64/libc.so.6
#4  0x00000000100ab8f2 in virtio_blk_handle_output (vdev=0x10ad57e8, 
vq=0x10eec270) at /home/cborntra/REPOS/qemu/hw/block/virtio-blk.c:595
#5  0x00000000100e18a4 in virtio_queue_notify_vq (vq=0x10eec270) at 
/home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1095
#6  0x00000000100e1906 in virtio_queue_notify (vdev=0x10ad57e8, n=0) at 
/home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1101
#7  0x00000000100f921c in virtio_ccw_hcall_notify (args=0x10e2aad0) at 
/home/cborntra/REPOS/qemu/hw/s390x/s390-virtio-ccw.c:66
#8  0x00000000100ee518 in s390_virtio_hypercall (env=0x10e2aac0) at 
/home/cborntra/REPOS/qemu/hw/s390x/s390-virtio-hcall.c:35
#9  0x000000001014192e in handle_hypercall (cpu=0x10e227f0, run=0x3ff84280000) 
at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:1283
#10 0x0000000010141c36 in handle_diag (cpu=0x10e227f0, run=0x3ff84280000, 
ipb=83886080) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:1352
#11 0x00000000101431b6 in handle_instruction (cpu=0x10e227f0, 
run=0x3ff84280000) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:1799
#12 0x00000000101433ee in handle_intercept (cpu=0x10e227f0) at 
/home/cborntra/REPOS/qemu/target-s390x/kvm.c:1842
#13 0x0000000010143c22 in kvm_arch_handle_exit (cs=0x10e227f0, 
run=0x3ff84280000) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:2028
#14 0x000000001007b5aa in kvm_cpu_exec (cpu=0x10e227f0) at 
/home/cborntra/REPOS/qemu/kvm-all.c:1921
#15 0x000000001005bd92 in qemu_kvm_cpu_thread_fn (arg=0x10e227f0) at 
/home/cborntra/REPOS/qemu/cpus.c:1050
#16 0x000003ff86b87c2c in start_thread () at /lib64/libpthread.so.0
#17 0x000003ff86a8ec9a in thread_start () at /lib64/libc.so.6


trace 2 (compiled on F23)

Thread 5 (Thread 0x3ffb897f910 (LWP 37895)):
#0  0x000003ffba00841e in syscall () at /lib64/libc.so.6
#1  0x00000000803d5306 in futex_wait (ev=0x80a4a104 <rcu_call_ready_event>, 
val=4294967295) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:292
#2  0x00000000803d5596 in qemu_event_wait (ev=0x80a4a104 
<rcu_call_ready_event>) at 
/home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:399
#3  0x00000000803f2c3c in call_rcu_thread (opaque=0x0) at 
/home/cborntra/REPOS/qemu/util/rcu.c:250
#4  0x000003ffba107c2c in start_thread () at /lib64/libpthread.so.0
#5  0x000003ffba00ec9a in thread_start () at /lib64/libc.so.6

Thread 4 (Thread 0x3ffb574a910 (LWP 37907)):
#0  0x000003ffba00334a in ioctl () at /lib64/libc.so.6
#1  0x0000000080081a44 in kvm_vcpu_ioctl (cpu=0x80b4b970, type=44672) at 
/home/cborntra/REPOS/qemu/kvm-all.c:1984
#2  0x000000008008130c in kvm_cpu_exec (cpu=0x80b4b970) at 
/home/cborntra/REPOS/qemu/kvm-all.c:1834
#3  0x000000008006074c in qemu_kvm_cpu_thread_fn (arg=0x80b4b970) at 
/home/cborntra/REPOS/qemu/cpus.c:1050
#4  0x000003ffba107c2c in start_thread () at /lib64/libpthread.so.0
#5  0x000003ffba00ec9a in thread_start () at /lib64/libc.so.6

Thread 3 (Thread 0x3ffb5f4a910 (LWP 37906)):
#0  0x000003ffb9f3f5b2 in sigtimedwait () at /lib64/libc.so.6
#1  0x000000008005fcda in qemu_kvm_eat_signals (cpu=0x80e587f0) at 
/home/cborntra/REPOS/qemu/cpus.c:804
#2  0x00000000800605fc in qemu_kvm_wait_io_event (cpu=0x80e587f0) at 
/home/cborntra/REPOS/qemu/cpus.c:1019
#3  0x000000008006077a in qemu_kvm_cpu_thread_fn (arg=0x80e587f0) at 
/home/cborntra/REPOS/qemu/cpus.c:1055
#4  0x000003ffba107c2c in start_thread () at /lib64/libpthread.so.0
#5  0x000003ffba00ec9a in thread_start () at /lib64/libc.so.6

Thread 2 (Thread 0x3ffbbbdbb90 (LWP 37839)):
#0  0x000003ffba110cd4 in __lll_lock_wait () at /lib64/libpthread.so.0
#1  0x000003ffba113ed4 in __lll_lock_elision () at /lib64/libpthread.so.0
#2  0x00000000803d49d6 in qemu_mutex_lock (mutex=0x8061f260 
<qemu_global_mutex>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:64
#3  0x0000000080060ef4 in qemu_mutex_lock_iothread () at 
/home/cborntra/REPOS/qemu/cpus.c:1226
#4  0x00000000802eeae4 in os_host_main_loop_wait (timeout=1291000000) at 
/home/cborntra/REPOS/qemu/main-loop.c:254
#5  0x00000000802eebf6 in main_loop_wait (nonblocking=0) at 
/home/cborntra/REPOS/qemu/main-loop.c:505
#6  0x000000008017b4bc in main_loop () at /home/cborntra/REPOS/qemu/vl.c:1933
#7  0x00000000801839aa in main (argc=72, argv=0x3ffda07e4b8, 
envp=0x3ffda07e700) at /home/cborntra/REPOS/qemu/vl.c:4656

Thread 1 (Thread 0x3ffb817f910 (LWP 37897)):
#0  0x000003ffb9f3e2c0 in raise () at /lib64/libc.so.6
#1  0x000003ffb9f3fc26 in abort () at /lib64/libc.so.6
#2  0x000003ffb9f35bce in __assert_fail_base () at /lib64/libc.so.6
#3  0x000003ffb9f35c5c in  () at /lib64/libc.so.6
#4  0x00000000800b4ee2 in virtio_blk_handle_output (vdev=0x80e51468, 
vq=0x80f3e280) at /home/cborntra/REPOS/qemu/hw/block/virtio-blk.c:595
#5  0x00000000800ef434 in virtio_queue_notify_vq (vq=0x80f3e280) at 
/home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1095
#6  0x00000000800f1cf4 in virtio_queue_host_notifier_read (n=0x80f3e2d8) at 
/home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1785
#7  0x00000000802f1cdc in aio_dispatch (ctx=0x80ab1050) at 
/home/cborntra/REPOS/qemu/aio-posix.c:327
#8  0x00000000802f2662 in aio_poll (ctx=0x80ab1050, blocking=false) at 
/home/cborntra/REPOS/qemu/aio-posix.c:475
#9  0x0000000080163942 in iothread_run (opaque=0x80ab0b10) at 
/home/cborntra/REPOS/qemu/iothread.c:46
#10 0x000003ffba107c2c in start_thread () at /lib64/libpthread.so.0
#11 0x000003ffba00ec9a in thread_start () at /lib64/libc.so.6
(gdb)