Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932146AbaAUPkj (ORCPT ); Tue, 21 Jan 2014 10:40:39 -0500 Received: from merlin.infradead.org ([205.233.59.134]:58307 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932087AbaAUPkh (ORCPT ); Tue, 21 Jan 2014 10:40:37 -0500 Date: Tue, 21 Jan 2014 16:39:58 +0100 From: Peter Zijlstra To: Waiman Long Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Arnd Bergmann , linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Steven Rostedt , Andrew Morton , Michel Lespinasse , Andi Kleen , Rik van Riel , "Paul E. McKenney" , Linus Torvalds , Raghavendra K T , George Spelvin , Tim Chen , aswin@hp.com, Scott J Norton Subject: Re: [PATCH v9 3/5] qrwlock, x86 - Treat all data type not bigger than long as atomic in x86 Message-ID: <20140121153958.GA31570@twins.programming.kicks-ass.net> References: <1389761047-47566-1-git-send-email-Waiman.Long@hp.com> <1389761047-47566-4-git-send-email-Waiman.Long@hp.com> <20140120150316.GG30183@twins.programming.kicks-ass.net> <52DE9410.6090500@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52DE9410.6090500@hp.com> 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 Tue, Jan 21, 2014 at 10:36:48AM -0500, Waiman Long wrote: > On 01/20/2014 10:03 AM, Peter Zijlstra wrote: > >On Tue, Jan 14, 2014 at 11:44:05PM -0500, Waiman Long wrote: > >>The generic __native_word() macro defined in include/linux/compiler.h > >>only allows "int" and "long" data types to be treated as native and > >>atomic. The x86 architecture, however, allow the use of char and short > >>data types as atomic as well. > >> > >>This patch extends the data type allowed in the __native_word() macro to > >>allow the use of char and short. > >> > >>Signed-off-by: Waiman Long > >>--- > >> arch/x86/include/asm/barrier.h | 8 ++++++++ > >> 1 files changed, 8 insertions(+), 0 deletions(-) > >> > >>diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h > >>index 04a4890..4d3e30a 100644 > >>--- a/arch/x86/include/asm/barrier.h > >>+++ b/arch/x86/include/asm/barrier.h > >>@@ -24,6 +24,14 @@ > >> #define wmb() asm volatile("sfence" ::: "memory") > >> #endif > >> > >>+/* > >>+ * All data types<= long are atomic in x86 > >>+ */ > >>+#ifdef __native_word > >>+#undef __native_word > >>+#endif > >>+#define __native_word(t) (sizeof(t)<= sizeof(long)) > >Yeah, not going to happen. > > Does explicit list of acceptable sizes work for you? > > #define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == > sizeof(short) || sizeof(t) == sizeof(int ) || > sizeof(t) == sizeof(long)) No, generic primitives should not have arch specific behaviour. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/