From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751714Ab2AZNb4 (ORCPT ); Thu, 26 Jan 2012 08:31:56 -0500 Received: from terminus.zytor.com ([198.137.202.10]:35947 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388Ab2AZNby (ORCPT ); Thu, 26 Jan 2012 08:31:54 -0500 Date: Thu, 26 Jan 2012 05:31:30 -0800 From: tip-bot for Jan Beulich Message-ID: Cc: acme@redhat.com, linux-kernel@vger.kernel.org, paulus@samba.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, jbeulich@suse.com, JBeulich@suse.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, linux-kernel@vger.kernel.org, acme@redhat.com, a.p.zijlstra@chello.nl, jbeulich@suse.com, JBeulich@suse.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <4F16D6FD020000780006D72F@nat28.tlf.novell.com> References: <4F16D6FD020000780006D72F@nat28.tlf.novell.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf bench: Make "default" memcpy() selection actually use glibc's implementation Git-Commit-ID: 9ea811973d49a1df0be04ff6e4df449e4fca4fb5 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Thu, 26 Jan 2012 05:31:36 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 9ea811973d49a1df0be04ff6e4df449e4fca4fb5 Gitweb: http://git.kernel.org/tip/9ea811973d49a1df0be04ff6e4df449e4fca4fb5 Author: Jan Beulich AuthorDate: Wed, 18 Jan 2012 13:28:13 +0000 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 24 Jan 2012 19:50:19 -0200 perf bench: Make "default" memcpy() selection actually use glibc's implementation Since arch/x86/lib/memcpy_64.S implements not only __memcpy, but also memcpy, without further precautions this function will get chose by the static linker for resolving all references, and hence the "default" measurement didn't really measure anything else than the "x86-64-unrolled" one. Fix this by renaming (through the pre-processor) the conflicting symbol. On my Westmere system, the glibc variant turns out to require about 4% less instructions, but 15% more cycles for the default 1Mb block size measured. Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/4F16D6FD020000780006D72F@nat28.tlf.novell.com Signed-off-by: Jan Beulich Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/bench/mem-memcpy-x86-64-asm.S | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S index a57b66e..384b607 100644 --- a/tools/perf/bench/mem-memcpy-x86-64-asm.S +++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S @@ -1,2 +1,2 @@ - +#define memcpy MEMCPY /* don't hide glibc's memcpy() */ #include "../../../arch/x86/lib/memcpy_64.S"