From: Theodore Tso Subject: Re: [RFC PATCH -V3 1/9] ext4: sparse fixes Date: Thu, 6 Nov 2008 17:09:54 -0500 Message-ID: <20081106220954.GM18939@mit.edu> References: <1225997374-10846-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: cmm@us.ibm.com, sandeen@redhat.com, linux-ext4@vger.kernel.org To: "Aneesh Kumar K.V" Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:42685 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750784AbYKFWJ7 (ORCPT ); Thu, 6 Nov 2008 17:09:59 -0500 Content-Disposition: inline In-Reply-To: <1225997374-10846-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Nov 07, 2008 at 12:19:26AM +0530, Aneesh Kumar K.V wrote: > #define EXT4_HAS_COMPAT_FEATURE(sb,mask) \ > - (EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) > + (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_compat) & mask) > #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask) \ > - (EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) > + (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) & mask) > #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask) \ > - (EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) > + (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) & mask) This is going to force a byte-swap instruction on every single big-endian system out there, which could potentially be costly, or at least undeed given that all of the times that these functions are called, the result gets used only as a booelan. Can we shut up sparse by using a explicit cast to an unsigned int? - Ted