From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932121AbbEHP2S (ORCPT ); Fri, 8 May 2015 11:28:18 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:57829 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753241AbbEHP2Q (ORCPT ); Fri, 8 May 2015 11:28:16 -0400 Date: Fri, 8 May 2015 17:27:59 +0200 From: Peter Zijlstra To: Arnaldo Carvalho de Melo Cc: Will Deacon , Ingo Molnar , David Ahern , Jiri Olsa , Namhyung Kim , Linux Kernel Mailing List Subject: Re: Question about barriers for ARM on tools/perf/ Message-ID: <20150508152759.GO27504@twins.programming.kicks-ass.net> References: <20150508140459.GI7862@kernel.org> <20150508142107.GA25587@arm.com> <20150508142513.GM27504@twins.programming.kicks-ass.net> <20150508143729.GJ7862@kernel.org> <20150508144820.GD25587@arm.com> <20150508145701.GL7862@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150508145701.GL7862@kernel.org> 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 Fri, May 08, 2015 at 11:57:01AM -0300, Arnaldo Carvalho de Melo wrote: > Em Fri, May 08, 2015 at 03:48:20PM +0100, Will Deacon escreveu: > > Do you know what the objection to the intrinsics was? I believe that > > the __sync versions are deprecated in favour of the C11-like __atomic > > flavours, so if that was all the objection was about then we could use > > one or the other depending on what the compiler supports. > > Peter? Ingo? I cannot remember, the __sync things should mostly work I suppose, and if you wrap then in the normal atomic interface we don't have to learn yet another API. That said, I've successfully lifted this kernel code into userspace in the past.