From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759477Ab2CTKR5 (ORCPT ); Tue, 20 Mar 2012 06:17:57 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:50632 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754451Ab2CTKQX (ORCPT ); Tue, 20 Mar 2012 06:16:23 -0400 X-IronPort-AV: E=Sophos;i="4.73,617,1325433600"; d="scan'208";a="4579991" From: Lai Jiangshan To: Christoph Lameter , Pekka Enberg , Matt Mackall , Tejun Heo , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Lai Jiangshan Subject: [RFC PATCH 1/6] kenrel.h: add ALIGN_OF_LAST_BIT() Date: Tue, 20 Mar 2012 18:21:19 +0800 Message-Id: <1332238884-6237-2-git-send-email-laijs@cn.fujitsu.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1332238884-6237-1-git-send-email-laijs@cn.fujitsu.com> References: <1332238884-6237-1-git-send-email-laijs@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-20 18:14:11, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-20 18:14:12, Serialize complete at 2012-03-20 18:14:12 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Get the biggest 2**y that x % (2**y) == 0 for the align value. Signed-off-by: Lai Jiangshan --- include/linux/kernel.h | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 5113462..2c439dc 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -44,6 +44,8 @@ #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) +#define ALIGN_OF_LAST_BIT(x) ((((x)^((x) - 1))>>1) + 1) + #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) /* -- 1.7.4.4