Re: [Qemu-devel] [PATCH] qemu-timer: remove unnecessary code

[Cao jin]

On 07/13/2016 07:40 PM, Paolo Bonzini wrote:
> On 13/07/2016 13:40, Cao jin wrote:
> > On 07/13/2016 06:21 PM, Paolo Bonzini wrote:
> > > On 13/07/2016 11:06, Cao jin wrote:
> > > > When passed argument 'ns' is 0, macro DIV_ROUND_UP will return 0 also.
> > >
> > > It's potentially slower though.
> >
> > Is it because the function in the i/o loop path, so the potentially
> > extra arithmetical instructions matters?
>
> It is quite common for ns to be zero, for example if a bottom half has
> to be invoked.

I see. I need dig deeper to understand the wholely I/O mechanism. Thanks 
Paolo!

> However, qemu_timeout_ns_to_ms is not used in the really important path
> (which is aio_poll in aio-posix.c) so I guess your patch is okay.
>
> Thanks,
>
> Paolo

--
Yours Sincerely,

Cao jin