From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx180.postini.com [74.125.245.180]) by kanga.kvack.org (Postfix) with SMTP id B0C0D6B0032 for ; Thu, 30 May 2013 15:18:14 -0400 (EDT) Message-ID: <51A7A5F3.4040704@sr71.net> Date: Thu, 30 May 2013 12:18:11 -0700 From: Dave Hansen MIME-Version: 1.0 Subject: Re: [PATCH] sparsemem: BUILD_BUG_ON when sizeof mem_section is non-power-of-2 References: <51A78EC4.4080703@intel.com> <1369939248-10006-1-git-send-email-cody@linux.vnet.ibm.com> In-Reply-To: <1369939248-10006-1-git-send-email-cody@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Cody P Schafer Cc: Andrew Morton , LKML , Linux MM , David Hansen On 05/30/2013 11:40 AM, Cody P Schafer wrote: > Instead of leaving a hidden trap for the next person who comes along and > wants to add something to mem_section, add a big fat warning about it > needing to be a power-of-2, and insert a BUILD_BUG_ON() in sparse_init() > to catch mistakes. > > Right now non-power-of-2 mem_sections cause a number of WARNs at boot > (which don't clearly point to the size of mem_section as an issue), but > the system limps on (temporarily, at least). > > This is based upon Dave Hansen's earlier RFC where he ran into the same > issue: > "sparsemem: fix boot when SECTIONS_PER_ROOT is not power-of-2" > http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/03077.html Thanks for doing that, Cody. At the risk of patting myself on the back: Acked-by: Dave Hansen -- 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