Re: [RFC] Unify KVM kernel-space and user-space code into a single project

[Anthony Liguori <anthony@codemonkey.ws>]

On 03/18/2010 06:48 AM, Ingo Molnar wrote:
> * Avi Kivity<avi@redhat.com>  wrote:
>
>    
>> On 03/18/2010 12:50 PM, Ingo Molnar wrote:
>>      
>>> * Avi Kivity<avi@redhat.com>   wrote:
>>>
>>>        
>>>>> The moment any change (be it as trivial as fixing a GUI detail or as
>>>>> complex as a new feature) involves two or more packages, development speed
>>>>> slows down to a crawl - while the complexity of the change might be very
>>>>> low!
>>>>>            
>>>> Why is that?
>>>>          
>>> It's very simple: because the contribution latencies and overhead compound,
>>> almost inevitably.
>>>        
>> It's not inevitable, if the projects are badly run, you'll have high
>> latencies, but projects don't have to be badly run.
>>      
> So the 64K dollar question is, why does Qemu still suck?
>    

Why does Linux AIO still suck?  Why do we not have a proper interface in 
userspace for doing asynchronous file system operations?

Why don't we have an interface in userspace to do zero-copy transmit and 
receive of raw network packets?

The lack of a decent userspace API for asynchronous file system 
operations is a huge usability problem for us.  Take a look at the 
complexity of our -drive option.  It's all because the kernel gives us 
sucky interfaces.

Regards,

Anthony Liguori