Re: [Qemu-devel] [RFC 0/8] arm AioContext with its own timer stuff

[Alex Bligh]

Liu,

--On 21 July 2013 16:42:57 +0800 Liu Ping Fan <address@hidden> wrote:

> Currently, the timers run on iothread within BQL, so virtio-block
> dataplane can not use throttle, as Stefan Hajnoczi pointed out in his
> patches to port dataplane onto block layer.(Thanks, Stefan) To enable
> this feature, I plan to enable timers to run on AioContext's thread. And
> maybe in future, hpet can run with its dedicated thread too.
>
> Also, I see Alex Bligh is on the same effort by another method,(it is a
> good idea)    "[RFC] aio/async: Add timed bottom-halves".

Stefan & Paolo did not like that method much, so I did a third method
(posted yesterday) suggested by Stefan which adds a clock to AioContext (to
which timers can be attached), deletes ALL the alarm_timer stuff (which was
very cathartic), uses timeouts on the g_poll, and adds ppoll where this is
available. Series at:
 http://lists.nongnu.org/archive/html/qemu-devel/2013-07/msg03334.html

I suspect this also overlaps with your code.

So now we have 3 methods to do similar things!

One advantage of my approach is that it removes more code than it adds
(by quite a margin). However, alarm timers could have been left in.
What's the advantage in giving an AioContext its own alarm timer as
opposed to just its own clock?

--
Alex Bligh