From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dong, Eddie" Subject: Re: QEMU PIC indirection patch for in-kernel APIC work Date: Thu, 5 Apr 2007 22:48:43 +0800 Message-ID: <0E6FE5D295DE5B4B8D9070C26A227987F24448@pdsmsx411.ccr.corp.intel.com> References: <64F9B87B6B770947A9F8391472E032160B319509@ehost011-8.exch011.intermedia.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: "Dor Laor" , "Anthony Liguori" , "Avi Kivity" Return-path: Content-class: urn:content-classes:message In-Reply-To: <64F9B87B6B770947A9F8391472E032160B319509-yEcIvxbTEBqsx+V+t5oei8rau4O3wl8o3fe8/T/H7NteoWH0uzbU5w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org 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 ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV