Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754320Ab0FYJTR (ORCPT ); Fri, 25 Jun 2010 05:19:17 -0400 Received: from one.firstfloor.org ([213.235.205.2]:49777 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752006Ab0FYJTP (ORCPT ); Fri, 25 Jun 2010 05:19:15 -0400 From: Andi Kleen To: KOSAKI Motohiro Cc: Nathan Fontenot , linux-kernel@vger.kernel.org Subject: Re: [PATCH] memory hotplug disable boot option References: <4C24012B.9030506@austin.ibm.com> <20100625105340.803C.A69D9226@jp.fujitsu.com> Date: Fri, 25 Jun 2010 11:19:13 +0200 In-Reply-To: <20100625105340.803C.A69D9226@jp.fujitsu.com> (KOSAKI Motohiro's message of "Fri, 25 Jun 2010 11:04:19 +0900 (JST)") Message-ID: <87d3vfeage.fsf@basil.nowhere.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 981 Lines: 25 KOSAKI Motohiro writes: >> Proposed patch to disable memory hotplug via a boot option, >> mem_hotplug=[on|off]. The patch only disables memory hotplug in that it >> prevents the creation of the memory sysfs directories for memory sections. >> >> This patch is meant to help alleviate very long boot times on systems with >> large memory (1+ TB) and many memory sections (10's of thousands). > > Why making simple /sys file is so slowly? Couldn't we fix such performance > problem? Yes I agree this really needs to be fixed properly, not hacked around with an option. Nathan can you please post some profile logs of the long boot times? -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/