From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk0-f54.google.com (mail-vk0-f54.google.com [209.85.213.54]) by kanga.kvack.org (Postfix) with ESMTP id 1AA166B025A for ; Fri, 25 Sep 2015 16:25:51 -0400 (EDT) Received: by vkgd64 with SMTP id d64so63094755vkg.0 for ; Fri, 25 Sep 2015 13:25:50 -0700 (PDT) Received: from mail-vk0-f47.google.com (mail-vk0-f47.google.com. [209.85.213.47]) by mx.google.com with ESMTPS id p138si2620563vkp.144.2015.09.25.13.25.49 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 25 Sep 2015 13:25:49 -0700 (PDT) Received: by vkao3 with SMTP id o3so62893082vka.2 for ; Fri, 25 Sep 2015 13:25:49 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4357538.Wlf88yQie6@vostro.rjw.lan> References: <20150925185256.GG5951@linux> <4331507.W3ZDWldbWu@vostro.rjw.lan> <4357538.Wlf88yQie6@vostro.rjw.lan> Date: Fri, 25 Sep 2015 13:25:49 -0700 Message-ID: Subject: Re: [PATCH V4 1/2] ACPI / EC: Fix broken 64bit big-endian users of 'global_lock' From: Viresh Kumar Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: "Rafael J. Wysocki" Cc: Johannes Berg , Greg Kroah-Hartman , Linaro Kernel Mailman List , QCA ath9k Development , Intel Linux Wireless , "linux-doc@vger.kernel.org" , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" , Linux ACPI , "open list:BLUETOOTH DRIVERS" , "open list:AMD IOMMU (AMD-VI)" , "netdev@vger.kernel.org" , "open list:NETWORKING DRIVERS (WIRELESS)" , "open list:TARGET SUBSYSTEM" , "open list:ULTRA-WIDEBAND (UWB) SUBSYSTEM:" , "open list:EDAC-CORE" , Linux Memory Management List , "moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEM..." On 25 September 2015 at 13:33, Rafael J. Wysocki wrote: > You're going to change that into bool in the next patch, right? Yeah. > So what if bool is a byte and the field is not word-aligned Its between two 'unsigned long' variables today, and the struct isn't packed. So, it will be aligned, isn't it? > and changing > that byte requires a read-modify-write. How do we ensure that things remain > consistent in that case? I didn't understood why a read-modify-write is special here? That's what will happen to most of the non-word-sized fields anyway? Probably I didn't understood what you meant.. -- viresh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org