Re: [Qemu-devel] [PATCH 08/12] Threadlet: Add aio_signal_handler threadlet API

["Venkateswararao Jujjuri (JV)" <jvrao@linux.vnet.ibm.com>]

On 1/17/2011 11:14 PM, Stefan Hajnoczi wrote:
> On Tue, Jan 18, 2011 at 6:46 AM, Arun R Bharadwaj
> <arun@linux.vnet.ibm.com> wrote:
>> * Stefan Hajnoczi <stefanha@gmail.com> [2011-01-18 06:31:34]:
>>
>>> On Tue, Jan 18, 2011 at 4:43 AM, Arun R Bharadwaj
>>> <arun@linux.vnet.ibm.com> wrote:
>>>> * Stefan Hajnoczi <stefanha@gmail.com> [2011-01-17 09:56:58]:
>>>>
>>>>> On Thu, Jan 13, 2011 at 12:14 PM, Arun R Bharadwaj
>>>>> <arun@linux.vnet.ibm.com> wrote:
>>>>>> +static void threadlet_io_completion_signal_handler(int signum)
>>>>>> +{
>>>>>> +    qemu_service_io();
>>>>>> +}
>>>>>> +
>>>>>> +static void threadlet_register_signal_handler(void)
>>>>>> +{
>>>>>> +    struct sigaction act;
>>>>>> +    sigfillset(&act.sa_mask);
>>>>>> +    act.sa_flags = 0; /* do not restart syscalls to interrupt select() */
>>>>>> +    act.sa_handler = threadlet_io_completion_signal_handler;
>>>>>> +    sigaction(SIGUSR2, &act, NULL);
>>>>>> +}
>>>>>> +
>>>>>> +void threadlet_init(void)
>>>>>> +{
>>>>>> +    threadlet_register_signal_handler();
>>>>>> +}
>>>>>
>>>>> This would be the right place to create qemu-threadlet.c, instead of
>>>>> adding the thread_init() prototype to qemu-thread.h and then including
>>>>> that in vl.c.
>>>>>
>>>>> Stefan
>>>>
>>>> I did not follow your comment here. How can we avoid including
>>>> threadler_init() in vl.c?
>>>
>>> Instead of adding threadlet_init() and related functions to
>>> posix-aio-compat.c and adding the prototype to qemu-thread.h, why not
>>> just create qemu-threadlet.c/qemu-threadlet.h and put these functions
>>> there instead?
>>>
>>> Stefan
>>
>> Got it. So you mean I merge patch 8 and patch 10 into a single patch.
>> But wouldn't this mean we are moving code and adding new API in the
>> same patch? Anthony did not want this from what I recall. But I can do
>> it if you feel it makes things simple.
> 
> I don't think you need to merge the patches.  It's odd to add
> functions to posix-aio-compat.c but put the prototype in qemu-thread.h
> (and then include and call from vl.c).  So for these three functions
> (threadlet_init, threadlet_register_signal_handler, and
> threadlet_io_completion_signal_handler) only I think it makes sense to
> move them to qemu-threadlet.[ch] straight away.

So basically create the new file qemu-threadlet.[ch] with only these functions
and move the rest of the code in patch 10(as we do now).
> 
> It's not the end of the world if you don't want to do that.  It just
> jumped out at me when reading and I had to remember that it'll get
> fixed up later.

Yes; as things are settling down towards the end of this series; I guess it is
OK if you decide
not to alter the sequence of the patches and avoid merges.

Thanks,
JV

> 
> Stefan
>