Re: [Qemu-devel] Main loop

[malc]

On Sat, 26 Sep 2009, Anthony Liguori wrote:

> malc wrote:
> > At http://repo.or.cz/w/qemu/malc.git?a=shortlog;h=refs/heads/mtloop you
> > can find the branch which refactors main execution loop somewhat, effects
> > include:
> > 
> > a. Host alarm timers are gone
> > b. IO thread is replaced (now Windows is supported too)
> >   
> 
> What was the motivation?

To have working audio on my 250 Hz system, where audio polling mode
ensures that wakeups happen at ~1Khz (with sufficiently small fragment
size) thus allowing Fast Tracker 2 to run properly. IOW this approach
allows to react to FD activity indpendantly of any timers.

Things i forgot to mention, slirp crawls (i.e. when sending some file
with nc to the guest the (hidden[1]) cpu utilization is only at ~50%
and subsequently it takes (relative to alarm mode) forever for transfer
to finnish, FWIW same problem plagues IO Thread)

This is the 5 or 6th internal iteration of the thing, at one point i had
a system working where tcg only held the locks during the IO/helpers, but
in the end complexity wasn't worth it.

-- 
mailto:address@hidden