From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754980Ab2BUBBr (ORCPT ); Mon, 20 Feb 2012 20:01:47 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:21430 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754909Ab2BUBBq (ORCPT ); Mon, 20 Feb 2012 20:01:46 -0500 X-Authority-Analysis: v=2.0 cv=fNy7LOme c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=ntpRP-UOdioA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=KWw57ePhm3b483ZPotsA:9 a=PUjeQqilurYA:10 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Message-ID: <1329786103.25686.48.camel@gandalf.stny.rr.com> Subject: Re: [PATCH] x86 fixes for 3.3 impacting distros (v1). From: Steven Rostedt To: Konrad Rzeszutek Wilk Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com Date: Mon, 20 Feb 2012 20:01:43 -0500 In-Reply-To: <1328888091-9692-1-git-send-email-konrad.wilk@oracle.com> References: <1328888091-9692-1-git-send-email-konrad.wilk@oracle.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.2.2-1 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-02-10 at 10:34 -0500, Konrad Rzeszutek Wilk wrote: > 66 66 66 90 data32 data32 xchg %ax,%ax > > [the 66 66 .. is 'nop']. Looks good right? Well, it does work very well on Intel > (used an i3 2100), but on AMD A8-3850 it hits a performance wall - that I found out > is a result of CONFIG_FUNCTION_TRACER (too many nops??) being compiled in (but the tracer > is set to the default 'nop'). If I disable that specific config option the numbers > are the same as the baseline (with CONFIG_FUNCTION_TRACER disabled) on the AMD box. > Interestingly enough I only see these on AMD machines - not on the Intel ones. All paravirt ops should be labeled with "notrace" so that function tracer does not trace those functions. Have you annotated your new paravirt ops with notrace? -- Steve