From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH RFC 2/2] kvm: Be courteous to other VMs in overcommitted scenario in PLE handler Date: Tue, 25 Sep 2012 12:11:45 +0200 Message-ID: <50618361.4070006@redhat.com> References: <20120921115942.27611.67488.sendpatchset@codeblue> <20120921120019.27611.66093.sendpatchset@codeblue> <50607BBE.8070507@redhat.com> <1348500861.11847.72.camel@twins> <50607F9B.7090701@redhat.com> <1348501929.11847.81.camel@twins> <50608323.9000603@redhat.com> <1348502757.11847.91.camel@twins> <50608608.4000507@redhat.com> <1348503219.11847.98.camel@twins> <50608887.7050204@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Raghavendra K T , "H. Peter Anvin" , Marcelo Tosatti , Ingo Molnar , Rik van Riel , Srikar , "Nikunj A. Dadhania" , KVM , Jiannan Ouyang , chegu vinod , "Andrew M. Theurer" , LKML , Srivatsa Vaddagiri , Gleb Natapov To: Peter Zijlstra Return-path: In-Reply-To: <50608887.7050204@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 09/24/2012 06:21 PM, Avi Kivity wrote: > On 09/24/2012 06:13 PM, Peter Zijlstra wrote: > > On Mon, 2012-09-24 at 18:10 +0200, Avi Kivity wrote: > >> > Its also still a LAPIC write -- disguised as an MSR though :/ > >> > >> It's probably a whole lot faster though. > > > > I've been told its not, I haven't tried it. > > I'll see if I can find a machine with it (don't see it on my Westmere, > it's probably on one of the Bridges. Or maybe the other Peter knows. > > Before measuring TSC_DEADLINE, I measured writing to TMICT, it costs 32 cycles. This is on a Sandy Bridge. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.