Re: [Qemu-devel] win7 bad i/o performance, high insn_emulation and exists

[Gleb Natapov]

On Tue, Feb 21, 2012 at 11:50:47AM +0100, Peter Lieven wrote:
> >I hope it will make Windows use TSC instead, but you can't be sure
> >about anything with Windows :(
> Whatever it does now it eates more CPU has almost equal
> number of exits and throughput is about the same (15MB/s).
> If pmtimer is at 0xb008 it still reads it like hell.
> 
> I checked with bcedit /v that useplatformclock is set to "No".
Yeah, today I noticed that it is likely virtio drivers that hammer
on PM timer (at least rip of the instruction that access it is
very close to rip of the instruction that access virtio pio).
Vadim, Windows driver developer,  is CCed.

> 
> I still wonder why both virtio devices are on IRQ0 ?
> 
They use MSI like they should.

--
                        Gleb.