Saw this intermittent as part of my ad-hoc CI test setup.
The backtrace says that the QEMU process has somehow hung
during 'realize' of the vhost-user device...
Process tree:
ubuntu 59552 0.0 0.0 5460 3120 ? S 06:51 0:00
\_ bash -o pipefail -c echo
'MALLOC_PERTURB_=${MALLOC_PERTURB_:-$(( ${RANDOM:-0} % 255 + 1))}
QTEST_QEMU_IMG=./qemu-img
G_TEST_DBUS_DAEMON=/home/ubuntu/qemu/tests/dbus-vmstate-daemon.sh
QTEST_QEMU_BINARY=./qemu-system-x86_64
QTEST_QEMU_STORAGE_DAEMON_BINARY=./storage-daemon/qemu-storage-daemon
tests/qtest/qos-test --tap -k' &&
MALLOC_PERTURB_=${MALLOC_PERTURB_:-$(( ${RANDOM:-0} % 255 + 1))}
QTEST_QEMU_IMG=./qemu-img
G_TEST_DBUS_DAEMON=/home/ubuntu/qemu/tests/dbus-vmstate-daemon.sh
QTEST_QEMU_BINARY=./qemu-system-x86_64
QTEST_QEMU_STORAGE_DAEMON_BINARY=./storage-daemon/qemu-storage-daemon
tests/qtest/qos-test --tap -k -m quick < /dev/null |
./scripts/tap-driver.pl --test-name="qtest-x86_64/qos-test"
ubuntu 59553 0.0 0.2 88008 8332 ? Sl 06:51 0:00
\_ tests/qtest/qos-test --tap -k -m quick
ubuntu 60122 0.0 0.5 254432 21516 ? Sl 06:51 0:00
| \_ ./storage-daemon/qemu-storage-daemon --blockdev
driver=file,node-name=disk0,filename=qtest.trJnuR --export
type=vhost-user-blk,id=disk0,addr.type=unix,addr.path=/tmp/qtest-59553-sock.iRt6WL,node-name=disk0,writable=on,num-queues=1
ubuntu 60123 0.0 1.6 747952 62732 ? Sl 06:51 0:00
| \_ ./qemu-system-x86_64 -qtest
unix:/tmp/qtest-59553.sock -qtest-log /dev/null -chardev
socket,path=/tmp/qtest-59553.qmp,id=char0 -mon
chardev=char0,mode=control -display none -M pc -device
vhost-user-blk-pci,id=drv0,chardev=char1,addr=4.0 -object
memory-backend-memfd,id=mem,size=256M,share=on -M memory-backend=mem
-m 256M -chardev socket,id=char1,path=/tmp/qtest-59553-sock.iRt6WL
-accel qtest
ubuntu 59554 0.0 0.2 14116 11204 ? S 06:51 0:00
\_ perl ./scripts/tap-driver.pl
--test-name=qtest-x86_64/qos-test
Backtrace, qemu process:
Thread 4 (Thread 0x3ff5be1d910 (LWP 60131)):
#0 0x000003ff7e2bed6a in __GI___sigtimedwait (set=<optimized out>,
set@entry=0x3ff5be1a098, info=info@entry=0x3ff5be19f68,
timeout=timeout@entry=0x0)
at ../sysdeps/unix/sysv/linux/sigtimedwait.c:42
#1 0x000003ff7e492ca8 in __sigwait (set=set@entry=0x3ff5be1a098,
sig=sig@entry=0x3ff5be1a094)
at ../sysdeps/unix/sysv/linux/sigwait.c:28
#2 0x000002aa16891ab2 in dummy_cpu_thread_fn
(arg=arg@entry=0x2aa182103e0) at ../../accel/dummy-cpus.c:46
#3 0x000002aa16b22f5a in qemu_thread_start (args=<optimized out>) at
../../util/qemu-thread-posix.c:541
#4 0x000003ff7e487aa8 in start_thread (arg=0x3ff5be1d910) at
pthread_create.c:463
#5 0x000003ff7e37a11e in thread_start () at
../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65
Thread 3 (Thread 0x3ff608b4910 (LWP 60130)):
#0 0x000003ff7e36f1b0 in __GI___poll (fds=0x3ff540031f0, nfds=3,
timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x000003ff7f9d2624 in () at /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#2 0x000003ff7f9d2aa8 in g_main_loop_run () at
/usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#3 0x000002aa1695ad26 in iothread_run
(opaque=opaque@entry=0x2aa17ea2b80) at ../../iothread.c:73
#4 0x000002aa16b22f5a in qemu_thread_start (args=<optimized out>) at
../../util/qemu-thread-posix.c:541
#5 0x000003ff7e487aa8 in start_thread (arg=0x3ff608b4910) at
pthread_create.c:463
#6 0x000003ff7e37a11e in thread_start () at
../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65
Thread 2 (Thread 0x3ff711b7910 (LWP 60129)):
#0 0x000003ff7e4911f6 in __lll_lock_wait
(futex=futex@entry=0x2aa17466bb8 <qemu_global_mutex>,
private=<optimized out>)
at lowlevellock.c:46
#1 0x000003ff7e48a204 in __GI___pthread_mutex_lock
(mutex=mutex@entry=0x2aa17466bb8 <qemu_global_mutex>)
at ../nptl/pthread_mutex_lock.c:80
#2 0x000002aa16b23116 in qemu_mutex_lock_impl (mutex=0x2aa17466bb8
<qemu_global_mutex>, file=0x2aa170a07d8 "../../util/rcu.c",
line=<optimized out>) at ../../util/qemu-thread-posix.c:79
#3 0x000002aa168221c0 in qemu_mutex_lock_iothread_impl
(file=file@entry=0x2aa170a07d8 "../../util/rcu.c",
line=line@entry=266)
at ../../softmmu/cpus.c:493
#4 0x000002aa16b4c8aa in call_rcu_thread (opaque=opaque@entry=0x0) at
../../util/rcu.c:266
#5 0x000002aa16b22f5a in qemu_thread_start (args=<optimized out>) at
../../util/qemu-thread-posix.c:541
#6 0x000003ff7e487aa8 in start_thread (arg=0x3ff711b7910) at
pthread_create.c:463
#7 0x000003ff7e37a11e in thread_start () at
../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65
Thread 1 (Thread 0x3ff81035470 (LWP 60123)):
#0 0x000003ff7e36f1b0 in __GI___poll (fds=0x2aa18147da0, nfds=2,
timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x000003ff7f9d2624 in () at /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#2 0x000003ff7f9d2aa8 in g_main_loop_run () at
/usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#3 0x000002aa169104de in vhost_user_read
(dev=dev@entry=0x2aa18f7afc8, msg=msg@entry=0x3ffc167ddfc)
at ../../hw/virtio/vhost-user.c:402
#4 0x000002aa1691186e in vhost_user_get_u64
(dev=dev@entry=0x2aa18f7afc8, request=request@entry=1,
u64=u64@entry=0x3ffc167e138)
at ../../hw/virtio/vhost-user.c:1334
#5 0x000002aa16913388 in vhost_user_get_features
(features=0x3ffc167e138, dev=0x2aa18f7afc8) at
../../hw/virtio/vhost-user.c:1356
#6 0x000002aa16913388 in vhost_user_backend_init (dev=0x2aa18f7afc8,
opaque=0x2aa18f7b240, errp=0x3ffc167e470)
at ../../hw/virtio/vhost-user.c:1877
#7 0x000002aa1684030c in vhost_dev_init
(hdev=hdev@entry=0x2aa18f7afc8, opaque=opaque@entry=0x2aa18f7b240,
backend_type=backend_type@entry=VHOST_BACKEND_TYPE_USER,
busyloop_timeout=busyloop_timeout@entry=0,
errp=errp@entry=0x3ffc167e470)
at ../../hw/virtio/vhost.c:1302
#8 0x000002aa168be742 in vhost_user_blk_connect
(dev=dev@entry=0x2aa18f7ad78, errp=errp@entry=0x3ffc167e470)
at ../../hw/block/vhost-user-blk.c:339
#9 0x000002aa168bec44 in vhost_user_blk_realize_connect
(errp=0x3ffc167e470, s=0x2aa18f7ad78) at
../../hw/block/vhost-user-blk.c:440
#10 0x000002aa168bec44 in vhost_user_blk_device_realize
(dev=0x2aa18f7ad78, errp=0x3ffc167e470)
at ../../hw/block/vhost-user-blk.c:513
#11 0x000002aa16819e78 in virtio_device_realize (dev=0x2aa18f7ad78,
errp=0x3ffc167e530) at ../../hw/virtio/virtio.c:3659
#12 0x000002aa169fcc50 in device_set_realized (obj=<optimized out>,
value=<optimized out>, errp=0x3ffc167e690)
at ../../hw/core/qdev.c:761
#13 0x000002aa169229ba in property_set_bool
(obj=obj@entry=0x2aa18f7ad78, v=v@entry=
0x2aa18fc41e0, name=name@entry=0x2aa16ccfd74 "realized",
opaque=0x2aa17f2a7a0, errp=errp@entry=0x3ffc167e690)
at ../../qom/object.c:2258
#14 0x000002aa16925534 in object_property_set
(obj=obj@entry=0x2aa18f7ad78, name=name@entry=0x2aa16ccfd74
"realized", v=v@entry=
0x2aa18fc41e0, errp=errp@entry=0x3ffc167e980) at ../../qom/object.c:1403
#15 0x000002aa1692229c in object_property_set_qobject
(obj=obj@entry=0x2aa18f7ad78, name=name@entry=0x2aa16ccfd74
"realized", value=value@entry=0x2aa18fc4120,
errp=errp@entry=0x3ffc167e980) at ../../qom/qom-qobject.c:28
#16 0x000002aa169257e2 in object_property_set_bool (obj=0x2aa18f7ad78,
name=0x2aa16ccfd74 "realized", value=<optimized out>,
errp=0x3ffc167e980) at ../../qom/object.c:1473
#17 0x000002aa1677e9c2 in virtio_pci_realize (pci_dev=0x2aa18f72b80,
errp=0x3ffc167e980) at ../../hw/virtio/virtio-pci.c:1907
#18 0x000002aa165dfc48 in pci_qdev_realize (qdev=0x2aa18f72b80,
errp=<optimized out>) at ../../hw/pci/pci.c:2148
#19 0x000002aa169fcc50 in device_set_realized (obj=<optimized out>,
value=<optimized out>, errp=0x3ffc167ebe8)
at ../../hw/core/qdev.c:761
#20 0x000002aa169229ba in property_set_bool
(obj=obj@entry=0x2aa18f72b80, v=v@entry=
0x2aa18fbe450, name=name@entry=0x2aa16ccfd74 "realized",
opaque=0x2aa17f2a7a0, errp=errp@entry=0x3ffc167ebe8)
at ../../qom/object.c:2258
#21 0x000002aa16925534 in object_property_set
(obj=obj@entry=0x2aa18f72b80, name=name@entry=0x2aa16ccfd74
"realized", v=v@entry=
0x2aa18fbe450, errp=errp@entry=0x2aa17484fe0 <error_fatal>) at
../../qom/object.c:1403
#22 0x000002aa1692229c in object_property_set_qobject
(obj=obj@entry=0x2aa18f72b80, name=name@entry=0x2aa16ccfd74
"realized", value=value@entry=0x2aa18fbe580,
errp=errp@entry=0x2aa17484fe0 <error_fatal>) at
../../qom/qom-qobject.c:28
#23 0x000002aa169257e2 in object_property_set_bool (obj=0x2aa18f72b80,
name=name@entry=0x2aa16ccfd74 "realized", value=value@entry=true,
errp=0x2aa17484fe0 <error_fatal>, errp@entry=<error reading variable:
value has been optimized out>) at ../../qom/object.c:1473
#24 0x000002aa169fb87e in qdev_realize (dev=<optimized out>,
bus=bus@entry=0x2aa18384200, errp=<error reading variable: value has
been optimized out>) at ../../hw/core/qdev.c:389
#25 0x000002aa165f1c6c in qdev_device_add (opts=<optimized out>,
errp=<optimized out>, errp@entry=0x2aa17484fe0 <error_fatal>)
at ../../softmmu/qdev-monitor.c:673
#26 0x000002aa168b2086 in device_init_func (opaque=<optimized out>,
opts=<optimized out>, errp=0x2aa17484fe0 <error_fatal>)
at ../../softmmu/vl.c:1187
#27 0x000002aa16b2b906 in qemu_opts_foreach (list=<optimized out>,
func=func@entry=0x2aa168b2068 <device_init_func>,
opaque=opaque@entry=0x0, errp=0x2aa17484fe0 <error_fatal>) at
../../util/qemu-option.c:1135
#28 0x000002aa168b5046 in qemu_create_cli_devices () at ../../softmmu/vl.c:2645
#29 0x000002aa168b5046 in qmp_x_exit_preconfig (errp=<optimized out>)
at ../../softmmu/vl.c:2693
#30 0x000002aa168b83ce in qemu_init (argc=<optimized out>,
argv=<optimized out>, envp=<optimized out>) at ../../softmmu/vl.c:3713
#31 0x000002aa1654f6da in main (argc=<optimized out>, argv=<optimized
out>, envp=<optimized out>) at ../../softmmu/main.c:49
Backtrace, qos-test:
Thread 2 (Thread 0x3ff9de7f910 (LWP 59555)):
#0 syscall () at ../sysdeps/unix/sysv/linux/s390/s390-64/syscall.S:53
#1 0x000002aa20c36a54 in qemu_futex_wait (val=<optimized out>,
f=<optimized out>) at /home/ubuntu/qemu/include/qemu/futex.h:29
#2 qemu_event_wait (ev=ev@entry=0x2aa20cdc3a0 <rcu_call_ready_event>)
at ../../util/qemu-thread-posix.c:480
#3 0x000002aa20c4efa4 in call_rcu_thread (opaque=opaque@entry=0x0) at
../../util/rcu.c:258
#4 0x000002aa20c35a6a in qemu_thread_start (args=<optimized out>) at
../../util/qemu-thread-posix.c:541
#5 0x000003ff9e887aa8 in start_thread (arg=0x3ff9de7f910) at
pthread_create.c:463
#6 0x000003ff9e77a11e in thread_start () at
../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65
Thread 1 (Thread 0x3ff9eef0940 (LWP 59553)):
#0 0x000003ff9e89165a in __libc_read (fd=<optimized out>,
buf=buf@entry=0x3ffc10fd3e0, nbytes=nbytes@entry=1024)
at ../sysdeps/unix/sysv/linux/read.c:27
#1 0x000002aa20bdee7a in read (__nbytes=1024, __buf=0x3ffc10fd3e0,
__fd=<optimized out>)
at /usr/include/s390x-linux-gnu/bits/unistd.h:44
#2 qtest_client_socket_recv_line (s=0x2aa22379fc0) at
../../tests/qtest/libqtest.c:494
#3 0x000002aa20bdf032 in qtest_rsp_args (s=s@entry=0x2aa22379fc0,
expected_args=expected_args@entry=1)
at ../../tests/qtest/libqtest.c:521
#4 0x000002aa20bdf6f2 in qtest_query_target_endianness
(s=0x2aa22379fc0) at ../../tests/qtest/libqtest.c:570
#5 0x000002aa20be0312 in qtest_init_without_qmp_handshake
(extra_args=<optimized out>) at ../../tests/qtest/libqtest.c:332
#6 0x000002aa20be09e2 in qtest_init (extra_args=<optimized out>) at
../../tests/qtest/libqtest.c:339
#7 0x000002aa20bc7b76 in qtest_start (
args=0x2aa22389ef0 "-M pc -device
vhost-user-blk-pci,id=drv0,chardev=char1,addr=4.0 -object
memory-backend-memfd,id=mem,size=256M,share=on -M memory-backend=mem
-m 256M -chardev socket,id=char1,path=/tmp/qtest-59553-so"...)
at ../../tests/qtest/libqtest-single.h:29
#8 restart_qemu_or_continue (
path=0x2aa22389ef0 "-M pc -device
vhost-user-blk-pci,id=drv0,chardev=char1,addr=4.0 -object
memory-backend-memfd,id=mem,size=256M,share=on -M memory-backend=mem
-m 256M -chardev socket,id=char1,path=/tmp/qtest-59553-so"...) at
../../tests/qtest/qos-test.c:105
#9 run_one_test (arg=<optimized out>) at ../../tests/qtest/qos-test.c:178
#10 0x000003ff9eb7c70c in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#11 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#12 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#13 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#14 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#15 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#16 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#17 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#18 0x000003ff9eb7c648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#19 0x000003ff9eb7c8ee in g_test_run_suite () from
/usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#20 0x000003ff9eb7c928 in g_test_run () from
/usr/lib/s390x-linux-gnu/libglib-2.0.so.0
#21 0x000002aa20bc6c9a in main (argc=<optimized out>, argv=<optimized
out>, envp=<optimized out>) at ../../tests/qtest/qos-test.c:338
Backtrace, qemu-storage-daemon:
Thread 2 (Thread 0x3ff951b7910 (LWP 60132)):
#0 syscall () at ../sysdeps/unix/sysv/linux/s390/s390-64/syscall.S:53
#1 0x000002aa0184fa6c in qemu_futex_wait (val=<optimized out>,
f=<optimized out>) at /home/ubuntu/qemu/include/qemu/futex.h:29
#2 qemu_event_wait (ev=ev@entry=0x2aa01971158 <rcu_call_ready_event>)
at ../../util/qemu-thread-posix.c:480
#3 0x000002aa0187498c in call_rcu_thread (opaque=opaque@entry=0x0) at
../../util/rcu.c:258
#4 0x000002aa0184ea82 in qemu_thread_start (args=<optimized out>) at
../../util/qemu-thread-posix.c:541
#5 0x000003ffa0507aa8 in start_thread (arg=0x3ff951b7910) at
pthread_create.c:463
#6 0x000003ffa03fa11e in thread_start () at
../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65
Thread 1 (Thread 0x3ffa14590e0 (LWP 60122)):
#0 0x000003ffa03ef302 in __GI_ppoll (fds=0x2aa0332b3d0, nfds=5,
timeout=<optimized out>, timeout@entry=0x0,
sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1 0x000002aa0185b054 in ppoll (__ss=0x0, __timeout=0x0,
__nfds=<optimized out>, __fds=<optimized out>)
at /usr/include/s390x-linux-gnu/bits/poll2.h:77
#2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>,
timeout=timeout@entry=-1) at ../../util/qemu-timer.c:336
#3 0x000002aa01851e48 in os_host_main_loop_wait (timeout=-1) at
../../util/main-loop.c:250
#4 main_loop_wait (nonblocking=<optimized out>) at ../../util/main-loop.c:531
#5 0x000002aa01738dda in main (argc=<optimized out>,
argv=0x3ffd28feba8) at ../../storage-daemon/qemu-storage-daemon.c:345
thanks
-- PMM
