On 02/02/2012 11:16 PM, Nikola Ciprich wrote: > Hello everybody, > > I'm a bit confused regarding windows guests and PIO.. some time ago, I was trying > to find out, why one of my windows guests was running terribly slow. > After checking the trace-cmd output, Avi stated that windows were using PIO instead > of DMA, after changing that, windows indeed got a lot faster. I didn't check traces > after that, but I'm now testing host with two windows 2003 guests, and checking the > trac-cmd output, I see a lot of kvm_pio calls. > While windows don't seem to be running particularly slow, they're not especially > fast either, and I'm wandering whether this could be related. But checking IDE > bus in guests, they seem to be using DMA which confuses me... > so my questions is, what are the kvm_pio operations I see in traces, and how can > I tell what is OK and what is wrong, regarding disks DMA/PIO? > If somebody could shed some light on this for me, I'd be very grateful... Not all PIO operations are DMA. Provide a trace and we can look. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
