Eric Blake <ebl...@redhat.com> writes: > On 04/05/2013 07:46 AM, Anthony Liguori wrote: >> The char-flow refactoring introduced a busy-wait that depended on >> an action from the VCPU thread. However, the VCPU thread could >> never take that action because the busy-wait starved the VCPU thread >> of the BQL because it never dropped the mutex while running select. >> >> Paolo doesn't want to drop this optimization for fear that we will >> stop detecting these busy waits. I'm afraid to keep this optimization >> even with the busy-wait fixed because I think a similar problem can >> occur just with heavy I/O thread load manifesting itself as VCPU pauses. >> >> As a compromise, introduce an artificial timeout after a thousand >> iterations but print a rate limited warning when this happens. This >> let's us still detect when this condition occurs without it being >> a fatal error. >> > >> + * print a message to the screen. If we run into this condition, create >> + * an fake timeout in order to give the VCPU threads a chance to run. > > s/an fake/a fake/
Drat, I proof read the commit message hoping to avoid such a mistake but should have reread the comment :-) Regards, Anthony Liguori > > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org
