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

Dor Laor
2007-04-05T14:41:30Z

>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?