From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 3/3] KVM: MMU: Separate trivial NULL check out from rmap_get_next() Date: Thu, 15 Mar 2012 15:46:31 +0200 Message-ID: <4F61F2B7.1020202@redhat.com> References: <20120315181856.2ced0a28.yoshikawa.takuya@oss.ntt.co.jp> <20120315182127.07600c50.yoshikawa.takuya@oss.ntt.co.jp> <4F61BB1D.6050209@redhat.com> <20120315191553.32d6fc36.yoshikawa.takuya@oss.ntt.co.jp> <4F61DA07.4010200@redhat.com> <20120315224142.67713f557239116a99cd18af@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Takuya Yoshikawa , mtosatti@redhat.com, kvm@vger.kernel.org To: Takuya Yoshikawa Return-path: Received: from mx1.redhat.com ([209.132.183.28]:44740 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753526Ab2CONqh (ORCPT ); Thu, 15 Mar 2012 09:46:37 -0400 In-Reply-To: <20120315224142.67713f557239116a99cd18af@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/15/2012 03:41 PM, Takuya Yoshikawa wrote: > > What I mean is, modern cpus effectively inline simple function calls by > > predicting the call, and branchs within the function, and the return, so > > they don't have to stop their pipelines at any of these points. But > > again, the numbers talk louder than speculation about cpu architecture. > > I need to update my knowledge, thank you! > > You can look at what's happening by doing perf record -a -f perf report using the TUI, select 'annotate rmap_get_next' You should see where the time is spent. -- error compiling committee.c: too many arguments to function