From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758771Ab2FPAVq (ORCPT ); Fri, 15 Jun 2012 20:21:46 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:20674 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757324Ab2FPAVZ (ORCPT ); Fri, 15 Jun 2012 20:21:25 -0400 X-Authority-Analysis: v=2.0 cv=eIiRfQV1 c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=XQbtiDEiEegA:10 a=R5I9ChW_JYgA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=ayC55rCoAAAA:8 a=rs3dCQBxvbIYi4zThekA:9 a=PUjeQqilurYA:10 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Message-ID: <1339806080.25903.68.camel@gandalf.stny.rr.com> Subject: Re: [PATCH tip/core/rcu 09/15] rcu: Increasing rcu_barrier() concurrency From: Steven Rostedt To: Josh Triplett Cc: "Paul E. McKenney" , linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, patches@linaro.org, "Paul E. McKenney" Date: Fri, 15 Jun 2012 20:21:20 -0400 In-Reply-To: <20120615233151.GA7613@leaf> References: <20120615210550.GA27506@linux.vnet.ibm.com> <1339794370-28119-1-git-send-email-paulmck@linux.vnet.ibm.com> <1339794370-28119-9-git-send-email-paulmck@linux.vnet.ibm.com> <20120615233151.GA7613@leaf> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.2.2-1+b1 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, 2012-06-15 at 16:31 -0700, Josh Triplett wrote: > > > - smp_mb(); /* Prevent any prior operations from leaking in. */ > > + /* > > + * Ensure tht all prior references, including to ->n_barrier_done, > > + * are ordered before the _rcu_barrier() machinery. > > + */ > > + smp_mb(); /* See above block comment. */ > > If checkpatch complains about the lack of a comment to the right of a > barrier even when the barrier has a comment directly above it, that > seems like a bug in checkpatch that needs fixing, to prevent developers > from having to add noise like "See above block comment.". :) Yuck yuck yuck yuck!!! Really, checkpatch is not the golden rule. I've copied an old checkpatch from something like 2.6.38 or so and use that today, where it was still reasonable. I've long abandoned the latest checkpatch, as it causes too many false positives. Or nazis like dictation. My rule of thumb is this. If what checkpatch tells you to do makes the format either uglier, or look stupid, it's a good idea to ignore the checkpatch complaint. I think in this case, you hit the latter. -- Steve