From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752374Ab3J3Pvd (ORCPT ); Wed, 30 Oct 2013 11:51:33 -0400 Received: from merlin.infradead.org ([205.233.59.134]:47510 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751351Ab3J3Pvb (ORCPT ); Wed, 30 Oct 2013 11:51:31 -0400 Date: Wed, 30 Oct 2013 16:51:16 +0100 From: Peter Zijlstra To: Victor Kaplansky Cc: paulmck@linux.vnet.ibm.com, Anton Blanchard , Benjamin Herrenschmidt , Frederic Weisbecker , LKML , Linux PPC dev , Mathieu Desnoyers , Michael Ellerman , Michael Neuling , Oleg Nesterov Subject: Re: perf events ring buffer memory barrier on powerpc Message-ID: <20131030155116.GO16117@laptop.programming.kicks-ass.net> References: <20131023141948.GB3566@localhost.localdomain> <20131025173749.GG19466@laptop.lan> <20131028132634.GO19466@laptop.lan> <20131028163418.GD4126@linux.vnet.ibm.com> <20131028201735.GA15629@redhat.com> <20131030092725.GL4126@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 30, 2013 at 03:28:54PM +0200, Victor Kaplansky wrote: > one of the authors of Documentation/memory-barriers.txt is on cc: list ;-) > > Disclaimer: it is anyway impossible to prove lack of *any* problem. > > Having said that, lets look into an example in > Documentation/circular-buffers.txt: > > We can see that authors of the document didn't put any memory barrier Note that both documents have the same author list ;-) Anyway, I didn't know about the circular thing, I suppose I should use CIRC_SPACE() thing :-) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from merlin.infradead.org (unknown [IPv6:2001:4978:20e::2]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 1D52E2C0379 for ; Thu, 31 Oct 2013 02:51:30 +1100 (EST) Date: Wed, 30 Oct 2013 16:51:16 +0100 From: Peter Zijlstra To: Victor Kaplansky Subject: Re: perf events ring buffer memory barrier on powerpc Message-ID: <20131030155116.GO16117@laptop.programming.kicks-ass.net> References: <20131023141948.GB3566@localhost.localdomain> <20131025173749.GG19466@laptop.lan> <20131028132634.GO19466@laptop.lan> <20131028163418.GD4126@linux.vnet.ibm.com> <20131028201735.GA15629@redhat.com> <20131030092725.GL4126@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: Michael Neuling , Mathieu Desnoyers , LKML , Oleg Nesterov , Linux PPC dev , Anton Blanchard , Frederic Weisbecker , paulmck@linux.vnet.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Oct 30, 2013 at 03:28:54PM +0200, Victor Kaplansky wrote: > one of the authors of Documentation/memory-barriers.txt is on cc: list ;-) > > Disclaimer: it is anyway impossible to prove lack of *any* problem. > > Having said that, lets look into an example in > Documentation/circular-buffers.txt: > > We can see that authors of the document didn't put any memory barrier Note that both documents have the same author list ;-) Anyway, I didn't know about the circular thing, I suppose I should use CIRC_SPACE() thing :-)