From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: Reducing I/O introduced domain scheduling Date: Tue, 12 Oct 2010 09:47:59 +0100 Message-ID: References: <1A42CE6F5F474C41B63392A5F80372B22FECF230@shsmsx501.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1A42CE6F5F474C41B63392A5F80372B22FECF230@shsmsx501.ccr.corp.intel.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Dong, Eddie" Cc: Paul Durrant , "xen-devel@lists.xensource.com" , "Zhang, Xiantao" , James Harper List-Id: xen-devel@lists.xenproject.org On 12/10/2010 08:19, "Dong, Eddie" wrote: >> First of all have you tested with PV drivers? Performance tests with >> no PV drivers are not that interesting. > > We used PV driver as more as possible, however the C disk in Windows guest > doesn't support PV yet. (A task in BIOS side or Win HAL side?) Running the system disk in PV mode certainly works okay with the Citrix PV drivers. Might this simply be a current limitation of the GPLPV drivers? If so, I definitely think you are better off putting effort into removing that limitation, rather than implementing your proposed optimisation. You will definitely get a bigger perf boost that way, and no suspicious hypervisor hacks needed. Cc'ing James Harper, who will best know what the current GPLPV drivers can/can't do. Also Paul Durrant, who can likely help with advice on how to PV up the Windows system disk. -- Keir