Re: qemu-kvm hangs if multipath device is queing

[Peter Lieven <pl@dlh.net>]

hi kevin,

here is the backtrace of (hopefully) all threads:

^C
Program received signal SIGINT, Interrupt.
[Switching to Thread 0x7f39b72656f0 (LWP 10695)]
0x00007f39b6c3ea94 in __lll_lock_wait () from /lib/libpthread.so.0

(gdb) thread apply all bt

Thread 2 (Thread 0x7f39b57b8950 (LWP 10698)):
#0  0x00007f39b6c3eedb in read () from /lib/libpthread.so.0
#1  0x000000000049e723 in qemu_laio_completion_cb (opaque=0x22b4010) at 
linux-aio.c:125
#2  0x000000000049e8ad in laio_cancel (blockacb=0x22ba310) at 
linux-aio.c:184
#3  0x000000000049a309 in bdrv_aio_cancel (acb=0x22ba310) at block.c:1800
#4  0x0000000000587a52 in dma_aio_cancel (acb=0x22ba170) at 
/usr/src/qemu-kvm-0.12.4/dma-helpers.c:138
#5  0x000000000049a309 in bdrv_aio_cancel (acb=0x22ba170) at block.c:1800
#6  0x0000000000444aac in ide_dma_cancel (bm=0x2800fd8) at 
/usr/src/qemu-kvm-0.12.4/hw/ide/core.c:2834
#7  0x0000000000445001 in bmdma_cmd_writeb (opaque=0x2800fd8, 
addr=49152, val=8) at /usr/src/qemu-kvm-0.12.4/hw/ide/pci.c:44
#8  0x00000000004c85f0 in ioport_write (index=0, address=49152, data=8) 
at ioport.c:80
#9  0x00000000004c8977 in cpu_outb (addr=49152, val=8 '\b') at ioport.c:198
#10 0x0000000000429731 in kvm_handle_io (port=49152, 
data=0x7f39b7263000, direction=1, size=1, count=1)
    at /usr/src/qemu-kvm-0.12.4/kvm-all.c:535
#11 0x000000000042bb8b in kvm_run (env=0x22ba5d0) at 
/usr/src/qemu-kvm-0.12.4/qemu-kvm.c:968
#12 0x000000000042cea2 in kvm_cpu_exec (env=0x22ba5d0) at 
/usr/src/qemu-kvm-0.12.4/qemu-kvm.c:1651
#13 0x000000000042d62c in kvm_main_loop_cpu (env=0x22ba5d0) at 
/usr/src/qemu-kvm-0.12.4/qemu-kvm.c:1893
#14 0x000000000042d76d in ap_main_loop (_env=0x22ba5d0) at 
/usr/src/qemu-kvm-0.12.4/qemu-kvm.c:1943
#15 0x00007f39b6c383ba in start_thread () from /lib/libpthread.so.0
#16 0x00007f39b5cbafcd in clone () from /lib/libc.so.6
#17 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f39b72656f0 (LWP 10695)):
#0  0x00007f39b6c3ea94 in __lll_lock_wait () from /lib/libpthread.so.0
#1  0x00007f39b6c3a190 in _L_lock_102 () from /lib/libpthread.so.0
#2  0x00007f39b6c39a7e in pthread_mutex_lock () from /lib/libpthread.so.0
#3  0x000000000042e739 in kvm_mutex_lock () at 
/usr/src/qemu-kvm-0.12.4/qemu-kvm.c:2524
#4  0x000000000042e76e in qemu_mutex_lock_iothread () at 
/usr/src/qemu-kvm-0.12.4/qemu-kvm.c:2537
#5  0x000000000040c262 in main_loop_wait (timeout=1000) at 
/usr/src/qemu-kvm-0.12.4/vl.c:3995
#6  0x000000000042dcf1 in kvm_main_loop () at 
/usr/src/qemu-kvm-0.12.4/qemu-kvm.c:2126
#7  0x000000000040c98c in main_loop () at /usr/src/qemu-kvm-0.12.4/vl.c:4212
#8  0x000000000041054b in main (argc=30, argv=0x7fff019f1ca8, 
envp=0x7fff019f1da0) at /usr/src/qemu-kvm-0.12.4/vl.c:6252