Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2011-08-23 16:02, Anthony Liguori wrote:
> On 08/23/2011 08:02 AM, Jan Kiszka wrote:
>> On 2011-08-23 14:40, Anthony Liguori wrote:
>>> You should be able to just use an eventfd or pipe.
>>>
>>> Better yet, we should look at using GThreadPool to replace posix-aio-compat.
>>
>> When interacting with the thread pool is part of some time-critical path
>> (easily possible with a real-time Linux guest), general-purpose
>> implementations like what glib offers are typically out of the game.
>> They do not provide sufficient customizability, specifically control
>> over their internal synchronization and allocation policies. That
>> applies to the other rather primitive glib threading and locking
>> services as well.
> 
> We can certainly enhance glib.  glib is a cross platform library.  I 

Do you want to carry forked glib bits in QEMU?

> don't see a compelling reason to invent a new cross platform library 
> just for QEMU especially if the justification is future features, not 
> current features.

Tweaking affinity of aio threads is already a current requirement.

And we already have a working threading and locking system. One that is
growing beyond glib's level of support quickly (think of RCU).

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux