Re: win7 bad i/o performance, high insn_emulation and exists

[Peter Lieven <pl@dlh.net>]

On 21.02.2012 17:48, Vadim Rozenfeld wrote:
>
> ----- Original Message -----
> From: "Peter Lieven"<pl@dlh.net>
> To: "Vadim Rozenfeld"<vrozenfe@redhat.com>
> Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, "Gleb Natapov"<gleb@redhat.com>
> Sent: Tuesday, February 21, 2012 4:10:22 PM
> Subject: Re: win7 bad i/o performance, high insn_emulation and exists
>
> On 21.02.2012 14:56, Vadim Rozenfeld wrote:
>> ----- Original Message -----
>> From: "Peter Lieven"<pl@dlh.net>
>> To: "Gleb Natapov"<gleb@redhat.com>
>> Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, vrozenfe@redhat.com
>> Sent: Tuesday, February 21, 2012 2:05:25 PM
>> Subject: Re: win7 bad i/o performance, high insn_emulation and exists
>>
>> On 21.02.2012 12:46, Gleb Natapov wrote:
>>> On Tue, Feb 21, 2012 at 12:16:16PM +0100, Peter Lieven wrote:
>>>> On 21.02.2012 12:00, Gleb Natapov wrote:
>>>>> On Tue, Feb 21, 2012 at 11:59:23AM +0100, Peter Lieven wrote:
>>>>>> On 21.02.2012 11:56, Gleb Natapov wrote:
>>>>>>> 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.
>>>>>> Ok, I will switch to IDE and e1000 to confirm this? Or does it not
>>>>>> make sense?
>>>>>>
>>>>> It make perfect sense! Please try it.
>>>> ~10MB/s. still a lot of 0xb008 reads.
>>>>
>> [VR]
>> Could it be that you have Driver Verifier running in you system?
>>
> unfortunately not.
>
> [VR]
> Then could you try booting into "Safe Mode"?
same picture.