Re: [Qemu-devel] coroutine: hung when using gthread backend

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

于 2013-3-27 0:21, Stefan Hajnoczi 写道:
> On Tue, Mar 26, 2013 at 11:03:53AM +0100, Paolo Bonzini wrote:
>> Il 26/03/2013 10:54, Stefan Hajnoczi ha scritto:
>>> On Tue, Mar 26, 2013 at 08:03:50AM +0100, Paolo Bonzini wrote:
>>>> Il 26/03/2013 03:50, Wenchao Xia ha scritto:
>>>>>    When I using tcg with coroutine backend = gthread,
>>>>> x86_64-softmmu/qemu-system-x86_64 will hung. Any one
>>>>> working on it?
>>>>
>>>> coroutine backend gthread hardly works for qemu, only qemu-io and qemu-img.
>>>
>>> Do you know why it doesn't work?
>>
>> Because it screws up the signals.  Coroutines can start in a thread and
>> later move to another.  If you use the gthread backend, coroutines keep
>> the signal mask of the thread where they were created.
>>
>> It is basically the same bug that was fixed in commit 6ab7e54 (Replace
>> all setjmp()/longjmp() with sigsetjmp()/siglongjmp(), 2013-02-20).
>
> That's interesting.  Maybe it can be fixed if the gthread backend is
> actually needed.
>
> Stefan
>
   If not hard I hope gthread backend works, since it works with gdb
and valgrind. I guess with default backend, gdb and valgrind need
some tricks to make they work.

-- 
Best Regards

Wenchao Xia