Re: [kvm-devel] [patch 2/2] QEMU: decrease console "refresh rate" with -nographic

[Marcelo T. <mto...@re...>]

On Tue, Apr 15, 2008 at 05:45:28PM +0300, Avi Kivity wrote:
> Anthony Liguori wrote:
> >
> >Why did we ever need sigtimedwait() anyway?  Even if we were 
> >select()ing within the VCPU context, we should break out of the 
> >select() on signal delivery.
> >
> 
> select() is no good since if the signal is delivered after the select(), 
> but before entry into guest mode, it is lost.  pselect() might work, but 
> its is not supported on all hosts, and it (AFAICT) delivers the signals 
> by calling their handlers, which is slow and unnecessary.

Anthony tested a patch using signalfd:

http://people.redhat.com/~mtosatti/io-thread-select-timeout

Which is only available on newer hosts. I guess the signals will have to
stay for older hosts.