[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Main loop

From: malc
Subject: Re: [Qemu-devel] Main loop
Date: Mon, 28 Sep 2009 22:50:32 +0400 (MSD)

On Mon, 28 Sep 2009, Glauber Costa wrote:

> > > Glauber spent some time with the IO thread recently.  Any reason you 
> > > didn't
> > > start with the existing IO thread (besides the fact that it doesn't work 
> > > with
> > > TCG)?
> > > 
> > 
> > Because i wasn't writing a replacement for IO Thread to begin with (btw it
> > does work with TCG), what it doesn't do is play nicely with icount[1], 
> > work on Windows, and for mysterious reasons still requires alarm timers, 
> > it also deadlocks for me when killing QEMU windows while running smp 
> > guest, but that's easily corrected mistake somewhere i guess.
> You wasn't, but you ended up doing so, since it is unlikely that they 
> will both live in the end. I am still reading your patch, and I still 
> have to struggle a little bit to understand it. Can you please tell us 
> why do you think your approach is better?
> The current I/O thread currently works with both kvm and tcg. For KVM, I 
> am quite close (expecting to post patches today) that enables the 
> in-kernel irqchip for it, and pretty close to do smp.
> Note that I don't think it requires alarm timers at all, by design. So, 
> again, why should we drop what we have in favour of your implementation?

Now that we have talked i see the problem and it basically boils down
to this: kvm can(and does) run multiple vcpus in multiple threads,
qemu always uses one, on top of this you are mainly interested in KVM
and i'm _only_ interested in TCG. The way i see it the best approach
would be to factor out main loop into separate file and let QEMU and
KVM go their own separate ways w.r.t. this new entity.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]