From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161811AbaKNTqs (ORCPT ); Fri, 14 Nov 2014 14:46:48 -0500 Received: from mail-ie0-f177.google.com ([209.85.223.177]:41793 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161184AbaKNTqr (ORCPT ); Fri, 14 Nov 2014 14:46:47 -0500 Message-ID: <54665C24.9060605@linaro.org> Date: Fri, 14 Nov 2014 13:46:44 -0600 From: Alex Elder User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Steven Rostedt CC: akpm@linux-foundation.org, bobby.prani@gmail.com, pmladek@suse.cz, jack@suse.cz, mcgrof@suse.com, joe@perches.com, linux-kernel@vger.kernel.org, Jiri Kosina Subject: Re: [PATCH] printk: drop logbuf_cpu volatile qualifier References: <1415992771-9071-1-git-send-email-elder@linaro.org> <20141114144515.5b3e7d32@gandalf.local.home> In-Reply-To: <20141114144515.5b3e7d32@gandalf.local.home> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/14/2014 01:45 PM, Steven Rostedt wrote: > On Fri, 14 Nov 2014 13:19:31 -0600 > Alex Elder wrote: > >> Pranith Kumar posted a patch in which removed the "volatile" >> qualifier for the "logbuf_cpu" variable in vprintk_emit(). >> https://lkml.org/lkml/2014/11/13/894 >> In his patch, he used ACCESS_ONCE() for all references to >> that symbol to provide whatever protection was intended. >> >> There was some discussion that followed, and in the end >> Stephen Rostedt concluded that not only was "volatile" not > > I don't know of a Stephen Rostedt. J Sorry. I'm sure that's a source of annoyance. -Alex >> needed, neither was it required to use ACCESS_ONCE(). I >> offered an elaborate description that concluded Stephen > > Who is this Stephen you talk about? . . .