Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756752Ab0ANPmP (ORCPT ); Thu, 14 Jan 2010 10:42:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754583Ab0ANPmO (ORCPT ); Thu, 14 Jan 2010 10:42:14 -0500 Received: from terminus.zytor.com ([198.137.202.10]:47471 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754348Ab0ANPmO (ORCPT ); Thu, 14 Jan 2010 10:42:14 -0500 Message-ID: <4B4F3A1A.2030906@zytor.com> Date: Thu, 14 Jan 2010 07:36:58 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-3.fc11 Thunderbird/3.0 MIME-Version: 1.0 To: rostedt@goodmis.org CC: Jason Baron , linux-kernel@vger.kernel.org, mingo@elte.hu, mathieu.desnoyers@polymtl.ca, tglx@linutronix.de, andi@firstfloor.org, roland@redhat.com, rth@redhat.com, mhiramat@redhat.com, Arjan van de Ven Subject: Re: [RFC PATCH 2/8] jump label v4 - x86: Introduce generic jump patching without stop_machine References: <1263483139.28171.3857.camel@gandalf.stny.rr.com> In-Reply-To: <1263483139.28171.3857.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 771 Lines: 24 On 01/14/2010 07:32 AM, Steven Rostedt wrote: >> + >> + /* Replacing 1 byte can be done atomically. */ >> + if (unlikely(len <= 1)) >> + return text_poke(addr, opcode, len); > > This part bothers me. The text_poke just writes over the text directly > (using a separate mapping). But if that memory is in the pipeline of > another CPU, I think this could cause a GPF. > Could you clarify why you think that? -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/