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From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	tu bo <tubo@linux.vnet.ibm.com>, Fam Zheng <famz@redhat.com>,
	qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
	cornelia.huck@de.ibm.com, Stefan Hajnoczi <stefanha@redhat.com>,
	qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 0/4] Tweaks around virtio-blk start/stop
Date: Thu, 17 Mar 2016 16:15:46 +0100	[thread overview]
Message-ID: <56EACA22.2020505@de.ibm.com> (raw)
In-Reply-To: <56EAC706.2040006@redhat.com>

On 03/17/2016 04:02 PM, Paolo Bonzini wrote:
> 
> 
> On 17/03/2016 13:39, Christian Borntraeger wrote:
>> As an interesting side note, I updated my system from F20 to F23 some days ago
>> (after the initial report). While To Bo is still on a F20 system. I was not able
>> to reproduce the original crash on f23. but going back to F20 made this
>> problem re-appear.
>>  
>>   Stack trace of thread 26429:
>>                 #0  0x00000000802008aa tracked_request_begin (qemu-system-s390x)
>>                 #1  0x0000000080203f3c bdrv_co_do_preadv (qemu-system-s390x)
>>                 #2  0x000000008020567c bdrv_co_do_readv (qemu-system-s390x)
>>                 #3  0x000000008025d0f4 coroutine_trampoline (qemu-system-s390x)
>>                 #4  0x000003ff943d150a __makecontext_ret (libc.so.6)
>>
>> this is with patch 2-4 plus the removal of virtio_queue_host_notifier_read.
>>
>> Without removing virtio_queue_host_notifier_read, I get the same mutex lockup (as expected).
>>
>> Maybe we have two independent issues here and this is some old bug in glibc or
>> whatever?
> 
> I'm happy to try and reproduce on x86 if you give me some instruction
> (RHEL7 should be close enough to Fedora 20).
> 
> Can you add an assert in virtio_blk_handle_output to catch reentrancy, like

that was quick (let me know if I should recompile with debugging)

(gdb) thread apply all bt

Thread 5 (Thread 0x3ff7b8ff910 (LWP 236419)):
#0  0x000003ff7cdfcf56 in syscall () from /lib64/libc.so.6
#1  0x000000001022452e in futex_wait (val=<optimized out>, ev=<optimized out>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:292
#2  qemu_event_wait (ev=ev@entry=0x1082b5c4 <rcu_call_ready_event>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:399
#3  0x000000001023353a in call_rcu_thread (opaque=<optimized out>) at /home/cborntra/REPOS/qemu/util/rcu.c:250
#4  0x000003ff7cf084c6 in start_thread () from /lib64/libpthread.so.0
#5  0x000003ff7ce02ec2 in thread_start () from /lib64/libc.so.6

Thread 4 (Thread 0x3ff78eca910 (LWP 236426)):
#0  0x000003ff7cdf819a in ioctl () from /lib64/libc.so.6
#1  0x000000001005ddf8 in kvm_vcpu_ioctl (cpu=cpu@entry=0x10c27d40, type=type@entry=44672) at /home/cborntra/REPOS/qemu/kvm-all.c:1984
#2  0x000000001005df1c in kvm_cpu_exec (cpu=cpu@entry=0x10c27d40) at /home/cborntra/REPOS/qemu/kvm-all.c:1834
#3  0x000000001004b1be in qemu_kvm_cpu_thread_fn (arg=0x10c27d40) at /home/cborntra/REPOS/qemu/cpus.c:1050
#4  0x000003ff7cf084c6 in start_thread () from /lib64/libpthread.so.0
#5  0x000003ff7ce02ec2 in thread_start () from /lib64/libc.so.6

Thread 3 (Thread 0x3ff7e8dcbb0 (LWP 236395)):
#0  0x000003ff7cdf66e6 in ppoll () from /lib64/libc.so.6
#1  0x00000000101a5e08 in ppoll (__ss=0x0, __timeout=0x3ffd6afe8a0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#2  qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=1034000000) at /home/cborntra/REPOS/qemu/qemu-timer.c:325
#3  0x00000000101a56f2 in os_host_main_loop_wait (timeout=1034000000) at /home/cborntra/REPOS/qemu/main-loop.c:251
#4  main_loop_wait (nonblocking=<optimized out>) at /home/cborntra/REPOS/qemu/main-loop.c:505
#5  0x00000000100136d6 in main_loop () at /home/cborntra/REPOS/qemu/vl.c:1933
#6  main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /home/cborntra/REPOS/qemu/vl.c:4656

Thread 2 (Thread 0x3ff7b0ff910 (LWP 236421)):
#0  0x000003ff7cdf66e6 in ppoll () from /lib64/libc.so.6
#1  0x00000000101a5e28 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#2  qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at /home/cborntra/REPOS/qemu/qemu-timer.c:313
#3  0x00000000101a727c in aio_poll (ctx=0x10880560, blocking=<optimized out>) at /home/cborntra/REPOS/qemu/aio-posix.c:453
#4  0x00000000100d39f0 in iothread_run (opaque=0x10880020) at /home/cborntra/REPOS/qemu/iothread.c:46
#5  0x000003ff7cf084c6 in start_thread () from /lib64/libpthread.so.0
#6  0x000003ff7ce02ec2 in thread_start () from /lib64/libc.so.6

Thread 1 (Thread 0x3ff57fff910 (LWP 236427)):
#0  0x000003ff7cd3b650 in raise () from /lib64/libc.so.6
#1  0x000003ff7cd3ced8 in abort () from /lib64/libc.so.6
#2  0x000003ff7cd33666 in __assert_fail_base () from /lib64/libc.so.6
#3  0x000003ff7cd336f4 in __assert_fail () from /lib64/libc.so.6
#4  0x000000001007a3c4 in virtio_blk_handle_output (vdev=<optimized out>, vq=<optimized out>) at /home/cborntra/REPOS/qemu/hw/block/virtio-blk.c:595
#5  0x000000001009390e in virtio_queue_notify_vq (vq=0x10d77c70) at /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1095
#6  0x0000000010095894 in virtio_queue_notify_vq (vq=<optimized out>) at /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1091
#7  virtio_queue_notify (vdev=<optimized out>, n=n@entry=0) at /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1101
#8  0x00000000100a17c8 in virtio_ccw_hcall_notify (args=<optimized out>) at /home/cborntra/REPOS/qemu/hw/s390x/s390-virtio-ccw.c:66
#9  0x000000001009c210 in s390_virtio_hypercall (env=env@entry=0x10c75aa0) at /home/cborntra/REPOS/qemu/hw/s390x/s390-virtio-hcall.c:35
#10 0x00000000100cb4e8 in handle_hypercall (run=<optimized out>, cpu=0x10c6d7d0) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:1283
#11 handle_diag (ipb=<optimized out>, run=0x3ff78680000, cpu=0x10c6d7d0) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:1352
#12 handle_instruction (run=0x3ff78680000, cpu=0x10c6d7d0) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:1799
#13 handle_intercept (cpu=0x10c6d7d0) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:1842
#14 kvm_arch_handle_exit (cs=cs@entry=0x10c6d7d0, run=run@entry=0x3ff78680000) at /home/cborntra/REPOS/qemu/target-s390x/kvm.c:2028
#15 0x000000001005df70 in kvm_cpu_exec (cpu=cpu@entry=0x10c6d7d0) at /home/cborntra/REPOS/qemu/kvm-all.c:1921
#16 0x000000001004b1be in qemu_kvm_cpu_thread_fn (arg=0x10c6d7d0) at /home/cborntra/REPOS/qemu/cpus.c:1050
#17 0x000003ff7cf084c6 in start_thread () from /lib64/libpthread.so.0
#18 0x000003ff7ce02ec2 in thread_start () from /lib64/libc.so.6

  parent reply	other threads:[~2016-03-17 15:15 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-16 10:10 [Qemu-devel] [PATCH 0/4] Tweaks around virtio-blk start/stop Fam Zheng
2016-03-16 10:10 ` [Qemu-devel] [PATCH 1/4] block: Use drained section in bdrv_set_aio_context Fam Zheng
2016-03-16 10:27   ` Paolo Bonzini
2016-03-16 10:51     ` Fam Zheng
2016-03-16 10:10 ` [Qemu-devel] [PATCH 2/4] block-backend: Introduce blk_drained_begin/end Fam Zheng
2016-03-16 10:10 ` [Qemu-devel] [PATCH 3/4] virtio-blk: Use blk_drained_begin/end around dataplane stop Fam Zheng
2016-03-16 10:10 ` [Qemu-devel] [PATCH 4/4] virtio-blk: Clean up start/stop with mutex and BH Fam Zheng
2016-03-17 15:00   ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2016-03-17 15:07     ` Paolo Bonzini
2016-03-22 12:52       ` Fam Zheng
2016-03-22 18:05         ` Paolo Bonzini
2016-03-23  8:10           ` Cornelia Huck
2016-03-23  9:08             ` Paolo Bonzini
2016-03-23  9:12               ` Christian Borntraeger
2016-03-24  8:19                 ` tu bo
2016-03-24  8:32                   ` Cornelia Huck
2016-03-24  8:47                     ` Cornelia Huck
2016-03-24  9:31                       ` Cornelia Huck
2016-03-16 10:28 ` [Qemu-devel] [PATCH 0/4] Tweaks around virtio-blk start/stop Paolo Bonzini
2016-03-16 10:49   ` Christian Borntraeger
2016-03-16 11:09     ` Paolo Bonzini
2016-03-16 11:24       ` Christian Borntraeger
2016-03-16 12:55         ` Paolo Bonzini
2016-03-16 13:38           ` Christian Borntraeger
2016-03-16 13:45             ` Paolo Bonzini
2016-03-17  0:39               ` Fam Zheng
2016-03-17 11:03                 ` tu bo
2016-03-21 10:57                   ` Fam Zheng
2016-03-21 11:15                     ` Cornelia Huck
2016-03-21 12:45                       ` Fam Zheng
2016-03-21 13:02                         ` Cornelia Huck
2016-03-21 23:45                           ` Fam Zheng
2016-03-22  8:06                             ` Cornelia Huck
2016-03-22  7:10                     ` tu bo
2016-03-22  7:18                       ` Fam Zheng
2016-03-22  9:07                         ` Cornelia Huck
2016-03-22  9:46                           ` Paolo Bonzini
2016-03-22 11:59                             ` Cornelia Huck
2016-03-22 12:11                               ` Paolo Bonzini
2016-03-22 12:54                                 ` Cornelia Huck
2016-03-17 12:22             ` tu bo
2016-03-17 12:39               ` Christian Borntraeger
2016-03-17 13:02                 ` Cornelia Huck
2016-03-17 15:02                 ` Paolo Bonzini
2016-03-17 15:07                   ` Christian Borntraeger
2016-03-17 15:15                   ` Christian Borntraeger [this message]
2016-03-17 15:16                     ` Christian Borntraeger
2016-03-17 16:08                       ` Christian Borntraeger
2016-03-18 15:03                         ` Paolo Bonzini
2016-03-21  9:42                           ` Fam Zheng
2016-03-21 11:10                             ` Christian Borntraeger
2016-03-21 12:17                             ` Cornelia Huck
2016-03-21 13:47                           ` TU BO
2016-03-21 13:54                             ` Paolo Bonzini
2016-03-21 14:19                               ` Cornelia Huck
2016-03-22  0:31                                 ` Fam Zheng
2016-03-16 11:32       ` Cornelia Huck
2016-03-16 11:48         ` Paolo Bonzini
2016-03-16 11:56           ` Cornelia Huck
2016-03-16 11:59             ` Paolo Bonzini
2016-03-16 12:22               ` Cornelia Huck
2016-03-16 12:32                 ` Paolo Bonzini
2016-03-16 12:42                   ` Cornelia Huck
2016-03-16 12:49                     ` Paolo Bonzini
2016-03-16 13:04                       ` Cornelia Huck
2016-03-16 13:10                         ` Paolo Bonzini
2016-03-16 13:14                           ` Cornelia Huck
2016-03-16 13:15                             ` Paolo Bonzini
2016-03-16 11:52         ` Cornelia Huck
2016-03-16 11:54           ` Paolo Bonzini

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