Re: [Qemu-devel] slow speed for virtio-scsi since qemu 2.2

[Andrey Korolyov]

On Mon, Feb 16, 2015 at 5:47 PM, Stefan Priebe - Profihost AG
<address@hidden> wrote:
> Hi,
> Am 16.02.2015 um 15:44 schrieb Paolo Bonzini:
>>
>>
>> On 16/02/2015 15:43, Stefan Priebe - Profihost AG wrote:
>>> Hi,
>>>
>>> Am 16.02.2015 um 13:24 schrieb Paolo Bonzini:
>>>>
>>>>
>>>> On 15/02/2015 19:46, Stefan Priebe wrote:
>>>>>
>>>>> while i get a constant random 4k i/o write speed of 20.000 iops with
>>>>> qemu 2.1.0 or 2.1.3. I get jumping speeds with qemu 2.2 (jumping between
>>>>> 500 iops and 15.000 iop/s).
>>>>>
>>>>> If i use virtio instead of virtio-scsi speed is the same between 2.2 and
>>>>> 2.1.
>>>>
>>>> http://wiki.qemu.org/Contribute/ReportABug
>>>>
>>>> What is your command line?
>>>
>>> Could it be that this is a results of compiling qemu with --enable-debug
>>> to get debugging symbols?
>>
>> Yes.
>
> *urg* my fault - sorry. Is there a way to get debugging symbols without
> using enable-debug / getting slower performance?

Hi Stefan, splitdebug will help you there. Also this is a standard way
to ship debugging symbols in most distribuitions, so I wonder if you
may use just a generic build skeleton for this task...