From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754060Ab3J2KVy (ORCPT ); Tue, 29 Oct 2013 06:21:54 -0400 Received: from merlin.infradead.org ([205.233.59.134]:44475 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339Ab3J2KVx (ORCPT ); Tue, 29 Oct 2013 06:21:53 -0400 Date: Tue, 29 Oct 2013 11:21:31 +0100 From: Peter Zijlstra To: Victor Kaplansky Cc: Oleg Nesterov , Anton Blanchard , Benjamin Herrenschmidt , Frederic Weisbecker , LKML , Linux PPC dev , Mathieu Desnoyers , Michael Ellerman , Michael Neuling , "Paul E. McKenney" Subject: Re: perf events ring buffer memory barrier on powerpc Message-ID: <20131029102131.GA16117@laptop.programming.kicks-ass.net> References: <12083.1382486094@ale.ozlabs.ibm.com> <20131023141948.GB3566@localhost.localdomain> <20131025173749.GG19466@laptop.lan> <20131028132634.GO19466@laptop.lan> <20131028163418.GD4126@linux.vnet.ibm.com> <20131028201735.GA15629@redhat.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 Mon, Oct 28, 2013 at 10:58:58PM +0200, Victor Kaplansky wrote: > Oleg Nesterov wrote on 10/28/2013 10:17:35 PM: > > > mb(); // XXXXXXXX: do we really need it? I think yes. > > Oh, it is hard to argue with feelings. Also, it is easy to be on > conservative side and put the barrier here just in case. I'll make it a full mb for now and too am curious to see the end of this discussion explaining things ;-) 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 A2D4B2C0340 for ; Tue, 29 Oct 2013 21:21:50 +1100 (EST) Date: Tue, 29 Oct 2013 11:21:31 +0100 From: Peter Zijlstra To: Victor Kaplansky Subject: Re: perf events ring buffer memory barrier on powerpc Message-ID: <20131029102131.GA16117@laptop.programming.kicks-ass.net> References: <12083.1382486094@ale.ozlabs.ibm.com> <20131023141948.GB3566@localhost.localdomain> <20131025173749.GG19466@laptop.lan> <20131028132634.GO19466@laptop.lan> <20131028163418.GD4126@linux.vnet.ibm.com> <20131028201735.GA15629@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: Michael Neuling , Mathieu Desnoyers , Oleg Nesterov , LKML , Linux PPC dev , Anton Blanchard , Frederic Weisbecker , "Paul E. McKenney" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Oct 28, 2013 at 10:58:58PM +0200, Victor Kaplansky wrote: > Oleg Nesterov wrote on 10/28/2013 10:17:35 PM: > > > mb(); // XXXXXXXX: do we really need it? I think yes. > > Oh, it is hard to argue with feelings. Also, it is easy to be on > conservative side and put the barrier here just in case. I'll make it a full mb for now and too am curious to see the end of this discussion explaining things ;-)