Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934516Ab3GRVjb (ORCPT ); Thu, 18 Jul 2013 17:39:31 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:35393 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759250Ab3GRVja (ORCPT ); Thu, 18 Jul 2013 17:39:30 -0400 Date: Thu, 18 Jul 2013 14:39:28 -0700 From: Andrew Morton To: Jerry Cc: zhuwei.lu@archermind.com, tianfu.huang@archermind.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: negative left shift count when PAGE_SHIFT > 20 Message-Id: <20130718143928.4f9b45807956e2fdb1ee3a22@linux-foundation.org> In-Reply-To: <1374166572-7988-1-git-send-email-uulinux@gmail.com> References: <1374166572-7988-1-git-send-email-uulinux@gmail.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 737 Lines: 17 On Fri, 19 Jul 2013 00:56:12 +0800 Jerry wrote: > When PAGE_SHIFT > 20, the result of "20 - PAGE_SHIFT" is negative. The > calculating here will generate an unexpected result. In addition, if > PAGE_SHIFT > 20, The memory size represented by numentries was already > integral multiple of 1MB. > If you tell me that you have a machine which has PAGE_SIZE=2MB and this was the only problem which prevented Linux from running on that machine then I'll apply the patch ;) -- 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/