Re: QEMU PIC indirection patch for in-kernel APIC work

Dong, Eddie
2007-04-05T14:48:43Z

Dor Laor wrote:
>> Dor Laor wrote:
>>>
>>> Do you know why Xen guy choose of implementing it in Xen? Why
>>> didn't they rip Qemu implementation?
>>>
>> With PIC in Xen, CPU2K gets 6.5% performance gain in old 1000HZ linux
>> kernel, KB gets 14% gain. We also did a shared PIC model which share
>> PIC state among Qemu & VMM with less LOC in VMM, it can get
>> similar performance gain (5.8% in my test).
>> BTW, at that time, PIT is in VMM already.
>> Eddie
>
> Thanks for the info, I suspected most chances the performance gain is
> small.
> So for the sake of the next arguments, what was the fuel running the
> decision of moving all the X-PI[c|t] things into the Xen?

Performance.
Thx, Eddie