Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751736AbaASA5J (ORCPT ); Sat, 18 Jan 2014 19:57:09 -0500 Received: from mail-ve0-f171.google.com ([209.85.128.171]:50665 "EHLO mail-ve0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751557AbaASA5H (ORCPT ); Sat, 18 Jan 2014 19:57:07 -0500 MIME-Version: 1.0 In-Reply-To: <20140118212227.GA10038@linux.vnet.ibm.com> References: <20140115023958.GA10038@linux.vnet.ibm.com> <20140115080753.GW31570@twins.programming.kicks-ass.net> <20140115205346.GF10038@linux.vnet.ibm.com> <20140115232134.GM31570@twins.programming.kicks-ass.net> <20140116103659.GO7572@laptop.programming.kicks-ass.net> <20140118100105.GV10038@linux.vnet.ibm.com> <20140118113406.GY30183@twins.programming.kicks-ass.net> <20140118122548.GX10038@linux.vnet.ibm.com> <20140118124136.GZ30183@twins.programming.kicks-ass.net> <20140118212227.GA10038@linux.vnet.ibm.com> Date: Sat, 18 Jan 2014 16:57:05 -0800 X-Google-Sender-Auth: 2RO_x2DA0XkfXkzQrkMltZHOKPU Message-ID: Subject: Re: [PATCH v8 4/4] qrwlock: Use smp_store_release() in write_unlock() From: Linus Torvalds To: Paul McKenney Cc: Peter Zijlstra , Matt Turner , Waiman Long , Linux Kernel , Ivan Kokshaysky , Daniel J Blueman , Richard Henderson Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 18, 2014 at 1:22 PM, Paul E. McKenney wrote: > > Yes, this requires that -all- updates to the fields in the machine word > in question use atomic rmw. Which would not be pretty from a core-code > perspective. Hence my suggestion of ceasing Linux-kernel support for > DEC Alpha CPUs that don't support byte operations. Also need 16-bit > operations as well, of course... I'm not seeing this. Why the hell would you have byte- or halfword-sized versions of the store_release or load_acquire things on alpha anyway? What it means is that data structures that do locking or atomics need to be "int" or "long" on alpha. That has always been true. What do you claim has changed? Linus -- 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/