From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: Seeking a KVM benchmark Date: Wed, 12 Nov 2014 16:51:56 +0100 Message-ID: <5463821C.2020900@redhat.com> References: <54608D77.2090907@redhat.com> <20141110104531.GB26187@minantech.com> <5460AC7C.8040409@redhat.com> <5460CA71.2050701@gmail.com> <5460F5B9.8030902@redhat.com> <20141110173835.GA26770@minantech.com> <5463458C.2070000@redhat.com> <20141112152204.GC26187@minantech.com> <54637C25.5000305@redhat.com> <20141112153230.GD26187@minantech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Cc: Avi Kivity , Andy Lutomirski , kvm list To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57635 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752377AbaKLPwG (ORCPT ); Wed, 12 Nov 2014 10:52:06 -0500 In-Reply-To: <20141112153230.GD26187@minantech.com> Sender: kvm-owner@vger.kernel.org List-ID: On 12/11/2014 16:32, Gleb Natapov wrote: > > > > userspace exit, urn 17560 17726 17628 17572 17417 > > > > lightweight exit, urn 3316 3342 3342 3319 3328 > > > > userspace exit, LOAD_EFER, guest!=host 12200 11772 12130 12164 12327 > > > > lightweight exit, LOAD_EFER, guest!=host 3214 3220 3238 3218 3337 > > > > userspace exit, LOAD_EFER, guest=host 11983 11780 11920 11919 12040 > > > > lightweight exit, LOAD_EFER, guest=host 3178 3193 3193 3187 3220 > > > > > > Is this with Andy's patch that skips LOAD_EFER when guest=host, or the one > > > that always switch LOAD_EFER? > > > > Skip LOAD_EFER when guest=host. > > So guest=host is a little bit better than guest!=host so looks like > skipping LOAD_EFER helps, but why "lightweight exit, urn" worse than > guest=host though, it should be exactly the same as long as NX bit is > the same in urn test, no? I don't know---it is very much reproducible though. It is not my machine so I cannot run perf on it, but I can try to find a similar one in the next few days. Paolo