Re: [Qemu-devel] Help with deadlock when using sound

[Peter Maydell]

On 6 May 2015 at 22:19, Programmingkid <address@hidden> wrote:
>
> On May 6, 2015, at 5:10 PM, Peter Maydell wrote:
>>> Thread 8 (process 29237):
>>> #0  tb_jmp_cache_hash_func (pc=1) at exec/exec-all.h:208
>>> #1  0x000000010000c9d7 in tb_find_slow (env=0x103846620, pc=133133655, 
>>> cs_base=133118944, flags=244) at 
>>> /Users/user/Documents/Development/Projects/Qemu/qemu-git/cpu-exec.c:309
>>> #2  0x000000010000cae3 in tb_find_fast (env=0x103846620) at 
>>> /Users/user/Documents/Development/Projects/Qemu/qemu-git/cpu-exec.c:327
>>> #3  0x000000010000cf66 in cpu_x86_exec (env=0x103846620) at 
>>> /Users/user/Documents/Development/Projects/Qemu/qemu-git/cpu-exec.c:485
>>> #4  0x000000010003978b in tcg_cpu_exec (env=0x103846620) at 
>>> /Users/user/Documents/Development/Projects/Qemu/qemu-git/cpus.c:1354
>>> #5  0x0000000100039878 in tcg_exec_all () at 
>>> /Users/user/Documents/Development/Projects/Qemu/qemu-git/cpus.c:1387
>>> #6  0x0000000100038dec in qemu_tcg_cpu_thread_fn (arg=0x10383e400) at 
>>> /Users/user/Documents/Development/Projects/Qemu/qemu-git/cpus.c:1032
>>> #7  0x00007fff8251bfd6 in _pthread_start ()
>>> #8  0x00007fff8251be89 in thread_start ()
>>
>> This backtrace says QEMU hasn't hung -- it is still executing
>> guest code (though possibly the guest has crashed or gone off
>> into the weeds, of course).
>
> If it were still executing guest code, then accessing the monitor
> would still work.

Well, that backtrace says we're executing code. We're not stuck
waiting for a lock, we're in the middle of the execution loop
(looking for a TB for PC=0x7ef7557). Your command line hasn't
redirected the monitor to the terminal or to a TCP port, so
possibly it's just that the GUI has got wedged? Try with
'-monitor stdio' and see if that's responsive.

I just tried on OSX and for me there's no hang -- the BIOS
boots normally, fails to find a valid image on the cdrom
and drops into attempting to network-boot, same behaviour
with or without -soundhw pcspk. (I build with coreaudio.)

-- PMM