From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 8BCAE6B0095 for ; Wed, 15 Dec 2010 04:26:05 -0500 (EST) Message-ID: <4D08899F.4050502@akana.de> Date: Wed, 15 Dec 2010 10:25:51 +0100 From: Ingo Korb MIME-Version: 1.0 Subject: Re: PROBLEM: __offline_isolated_pages may offline too many pages References: <4D0786D3.7070007@akana.de> <20101215092134.e2c8849f.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20101215092134.e2c8849f.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: linux-mm@kvack.org, akpm@linux-foundation.org, mel@csn.ul.ie, cl@linux-foundation.org, yinghai@kernel.org, andi.kleen@intel.com, linux-kernel@vger.kernel.org List-ID: On 15.12.2010 01:21, KAMEZAWA Hiroyuki wrote: > It's designed for offline memory section> MAX_ORDER. pageblock_nr_pages > is tend to be smaller than that. > > Do you see the problem with _exsisting_ user interface of memory hotplug ? > I think we have no control other than memory section. The existing, exported interface (remove_memory() - the check itself is in offline_pages()) only checks if both start and end of the to-be-removed block are aligned to pageblock_nr_pages. As you noted the actual size and alignment requirements in __offline_isolated_pages can be larger that that, so I think the checks in offline_pages() should be changed (if 1<= pageblock_nr_pages) or extended (if there can be any relation between the two). -ik -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org