From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC][PATCH 1/2] KVM: In-kernel PIT model Date: Thu, 24 Jan 2008 11:26:29 +0200 Message-ID: <479859C5.6010703@qumranet.com> References: <200801211718.23664.sheng.yang@intel.com> <200801231400.36063.sheng.yang@intel.com> <47970CEE.2050000@qumranet.com> <200801241729.18787.sheng.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: "Yang, Sheng" Return-path: In-Reply-To: <200801241729.18787.sheng.yang-ral2JQCrhuEAvxtiuMwx3w@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 Yang, Sheng wrote: > I updated patch using ktime_get() (Is it too heavy?). > > Shouldn't be. At least on modern hosts. > And currently all the muldiv64() is used to divide 1e9, which can be insteaded > by ">> 30" approximately. What's your opinion? > Accuracy is more important. And modern processors eat 64-bit divides for breakfast, they're certainly much less expensive than vmexits. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/