root@pvetst:~# gdb --batch --ex 't a a bt' -p $(cat /var/run/qemu-server/100.pid)
[New LWP 2434]
[New LWP 2535]
[New LWP 2536]
[New LWP 2537]
[New LWP 2538]
[New LWP 2539]
[New LWP 2542]
[New LWP 2592]
[New LWP 2593]
[New LWP 5474]
[New LWP 6979]
[New LWP 34483]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x000074015df78256 in __ppoll (fds=0x5c1d0bc64e60, nfds=11, timeout=<optimized out>, timeout@entry=0x7fff84304fd0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:42
42 ../sysdeps/unix/sysv/linux/ppoll.c: No such file or directory.
Thread 13 (Thread 0x7401598006c0 (LWP 34483) "iou-wrk-2537"):
#0 0x0000000000000000 in ?? ()
Backtrace stopped: Cannot access memory at address 0x0
Thread 12 (Thread 0x74015b51b480 (LWP 6979) "iou-wrk-2433"):
#0 0x0000000000000000 in ?? ()
Backtrace stopped: Cannot access memory at address 0x0
Thread 11 (Thread 0x74015a6006c0 (LWP 5474) "iou-wrk-2536"):
#0 0x0000000000000000 in ?? ()
Backtrace stopped: Cannot access memory at address 0x0
Thread 10 (Thread 0x740153e006c0 (LWP 2593) "iou-wrk-2539"):
#0 0x0000000000000000 in ?? ()
Backtrace stopped: Cannot access memory at address 0x0
Thread 9 (Thread 0x740158e006c0 (LWP 2592) "iou-wrk-2538"):
#0 0x0000000000000000 in ?? ()
Backtrace stopped: Cannot access memory at address 0x0
Thread 8 (Thread 0x73ff4b8006c0 (LWP 2542) "vnc_worker"):
#0 __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x5c1d0beb8e48) at ./nptl/futex-internal.c:57
#1 __futex_abstimed_wait_common (futex_word=futex_word@entry=0x5c1d0beb8e48, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0, cancel=cancel@entry=true) at ./nptl/futex-internal.c:87
#2 0x000074015df01efb in __GI___futex_abstimed_wait_cancelable64 (futex_word=futex_word@entry=0x5c1d0beb8e48, expected=expected@entry=0, clockid=clockid@entry=0, abstime=abstime@entry=0x0, private=private@entry=0) at ./nptl/futex-internal.c:139
#3 0x000074015df04558 in __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x5c1d0beb8e58, cond=0x5c1d0beb8e20) at ./nptl/pthread_cond_wait.c:503
#4 ___pthread_cond_wait (cond=cond@entry=0x5c1d0beb8e20, mutex=mutex@entry=0x5c1d0beb8e58) at ./nptl/pthread_cond_wait.c:618
#5 0x00005c1d0a5bbbbb in qemu_cond_wait_impl (cond=0x5c1d0beb8e20, mutex=0x5c1d0beb8e58, file=0x5c1d0a6701d4 "../ui/vnc-jobs.c", line=248) at ../util/qemu-thread-posix.c:225
#6 0x00005c1d09fd616b in vnc_worker_thread_loop (queue=queue@entry=0x5c1d0beb8e20) at ../ui/vnc-jobs.c:248
#7 0x00005c1d09fd6e48 in vnc_worker_thread (arg=arg@entry=0x5c1d0beb8e20) at ../ui/vnc-jobs.c:362
#8 0x00005c1d0a5bafc8 in qemu_thread_start (args=0x5c1d0beb8eb0) at ../util/qemu-thread-posix.c:541
#9 0x000074015df05134 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#10 0x000074015df857dc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
Thread 7 (Thread 0x740153e006c0 (LWP 2539) "CPU 3/KVM"):
#0 __GI___ioctl (fd=32, request=request@entry=44672) at ../sysdeps/unix/sysv/linux/ioctl.c:36
#1 0x00005c1d0a402a09 in kvm_vcpu_ioctl (cpu=cpu@entry=0x5c1d0bc9c3e0, type=type@entry=44672) at ../accel/kvm/kvm-all.c:3052
#2 0x00005c1d0a402f51 in kvm_cpu_exec (cpu=cpu@entry=0x5c1d0bc9c3e0) at ../accel/kvm/kvm-all.c:2869
#3 0x00005c1d0a404795 in kvm_vcpu_thread_fn (arg=arg@entry=0x5c1d0bc9c3e0) at ../accel/kvm/kvm-accel-ops.c:50
#4 0x00005c1d0a5bafc8 in qemu_thread_start (args=0x5c1d0bca5420) at ../util/qemu-thread-posix.c:541
#5 0x000074015df05134 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#6 0x000074015df857dc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
Thread 6 (Thread 0x740158e006c0 (LWP 2538) "CPU 2/KVM"):
#0 __GI___ioctl (fd=30, request=request@entry=44672) at ../sysdeps/unix/sysv/linux/ioctl.c:36
#1 0x00005c1d0a402a09 in kvm_vcpu_ioctl (cpu=cpu@entry=0x5c1d0bc92b60, type=type@entry=44672) at ../accel/kvm/kvm-all.c:3052
#2 0x00005c1d0a402f51 in kvm_cpu_exec (cpu=cpu@entry=0x5c1d0bc92b60) at ../accel/kvm/kvm-all.c:2869
#3 0x00005c1d0a404795 in kvm_vcpu_thread_fn (arg=arg@entry=0x5c1d0bc92b60) at ../accel/kvm/kvm-accel-ops.c:50
#4 0x00005c1d0a5bafc8 in qemu_thread_start (args=0x5c1d0bc9b9c0) at ../util/qemu-thread-posix.c:541
#5 0x000074015df05134 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#6 0x000074015df857dc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
Thread 5 (Thread 0x7401598006c0 (LWP 2537) "CPU 1/KVM"):
#0 __GI___ioctl (fd=28, request=request@entry=44672) at ../sysdeps/unix/sysv/linux/ioctl.c:36
#1 0x00005c1d0a402a09 in kvm_vcpu_ioctl (cpu=cpu@entry=0x5c1d0bc88260, type=type@entry=44672) at ../accel/kvm/kvm-all.c:3052
#2 0x00005c1d0a402f51 in kvm_cpu_exec (cpu=cpu@entry=0x5c1d0bc88260) at ../accel/kvm/kvm-all.c:2869
#3 0x00005c1d0a404795 in kvm_vcpu_thread_fn (arg=arg@entry=0x5c1d0bc88260) at ../accel/kvm/kvm-accel-ops.c:50
#4 0x00005c1d0a5bafc8 in qemu_thread_start (args=0x5c1d0bc92140) at ../util/qemu-thread-posix.c:541
#5 0x000074015df05134 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#6 0x000074015df857dc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
Thread 4 (Thread 0x74015a6006c0 (LWP 2536) "CPU 0/KVM"):
#0 __GI___ioctl (fd=26, request=request@entry=44672) at ../sysdeps/unix/sysv/linux/ioctl.c:36
#1 0x00005c1d0a402a09 in kvm_vcpu_ioctl (cpu=cpu@entry=0x5c1d0bc58530, type=type@entry=44672) at ../accel/kvm/kvm-all.c:3052
#2 0x00005c1d0a402f51 in kvm_cpu_exec (cpu=cpu@entry=0x5c1d0bc58530) at ../accel/kvm/kvm-all.c:2869
#3 0x00005c1d0a404795 in kvm_vcpu_thread_fn (arg=arg@entry=0x5c1d0bc58530) at ../accel/kvm/kvm-accel-ops.c:50
#4 0x00005c1d0a5bafc8 in qemu_thread_start (args=0x5c1d0b8b50b0) at ../util/qemu-thread-posix.c:541
#5 0x000074015df05134 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#6 0x000074015df857dc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
Thread 3 (Thread 0x74015b51b480 (LWP 2535) "vhost-2433"):
#0 0x0000000000000000 in ?? ()
Backtrace stopped: Cannot access memory at address 0x0
Thread 2 (Thread 0x74015b0006c0 (LWP 2434) "call_rcu"):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00005c1d0a5bc2ca in qemu_futex_wait (val=<optimized out>, f=<optimized out>) at ./include/qemu/futex.h:29
#2 qemu_event_wait (ev=ev@entry=0x5c1d0b4a3548 <rcu_call_ready_event>) at ../util/qemu-thread-posix.c:464
#3 0x00005c1d0a5c7222 in call_rcu_thread (opaque=opaque@entry=0x0) at ../util/rcu.c:278
#4 0x00005c1d0a5bafc8 in qemu_thread_start (args=0x5c1d0b8b9790) at ../util/qemu-thread-posix.c:541
#5 0x000074015df05134 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#6 0x000074015df857dc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
Thread 1 (Thread 0x74015b51b480 (LWP 2433) "kvm"):
#0 0x000074015df78256 in __ppoll (fds=0x5c1d0bc64e60, nfds=11, timeout=<optimized out>, timeout@entry=0x7fff84304fd0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:42
#1 0x00005c1d0a5d397e in ppoll (__ss=0x0, __timeout=0x7fff84304fd0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:64
#2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=990608) at ../util/qemu-timer.c:351
#3 0x00005c1d0a5d0dae in os_host_main_loop_wait (timeout=990608) at ../util/main-loop.c:305
#4 main_loop_wait (nonblocking=nonblocking@entry=0) at ../util/main-loop.c:589
#5 0x00005c1d0a1eb1a9 in qemu_main_loop () at ../system/runstate.c:783
#6 0x00005c1d0a40e226 in qemu_default_main () at ../system/main.c:37
#7 0x000074015dea324a in __libc_start_call_main (main=main@entry=0x5c1d09f898e0 <main>, argc=argc@entry=74, argv=argv@entry=0x7fff843051e8) at ../sysdeps/nptl/libc_start_call_main.h:58
#8 0x000074015dea3305 in __libc_start_main_impl (main=0x5c1d09f898e0 <main>, argc=74, argv=0x7fff843051e8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff843051d8) at ../csu/libc-start.c:360
#9 0x00005c1d09f8b621 in _start ()
[Inferior 1 (process 2433) detached]
root@pvetst:~#