From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFC PATCH 03/15] Provide atomic_t functions implemented with ISO-C++11 atomics Date: Thu, 19 May 2016 09:45:36 +0200 Message-ID: <20160519074536.GR3193@twins.programming.kicks-ass.net> References: <146358423711.8596.9104061348359986393.stgit@warthog.procyon.org.uk> <146358425972.8596.7418861336334796772.stgit@warthog.procyon.org.uk> <20160518173218.GE3206@twins.programming.kicks-ass.net> <1463643409.6885.5.camel@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from merlin.infradead.org ([205.233.59.134]:38898 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751513AbcESHpq (ORCPT ); Thu, 19 May 2016 03:45:46 -0400 Content-Disposition: inline In-Reply-To: <1463643409.6885.5.camel@infradead.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: David Woodhouse Cc: David Howells , linux-arch@vger.kernel.org, x86@kernel.org, will.deacon@arm.com, linux-kernel@vger.kernel.org, ramana.radhakrishnan@arm.com, paulmck@linux.vnet.ibm.com On Thu, May 19, 2016 at 08:36:49AM +0100, David Woodhouse wrote: > On Wed, 2016-05-18 at 19:32 +0200, Peter Zijlstra wrote: > > > > Does this generate 'sane' code for LL/SC archs? That is, a single LL/SC > > loop and not a loop around an LL/SC cmpxchg. > > The whole point of using compiler intrinsics and letting the compiler > actually see what's going on... is that it bloody well should :) Should and does be two different things of course ;-)