From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id D9D066B002C for ; Mon, 10 Oct 2011 18:00:43 -0400 (EDT) Received: by gya6 with SMTP id 6so7865903gya.14 for ; Mon, 10 Oct 2011 15:00:42 -0700 (PDT) Date: Mon, 10 Oct 2011 15:00:38 -0700 From: Andrew Morton Subject: Re: [PATCH] mm: memory hotplug: Check if pages are correctly reserved on a per-section basis Message-Id: <20111010150038.ac161977.akpm@linux-foundation.org> In-Reply-To: <20111010071119.GE6418@suse.de> References: <20111010071119.GE6418@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: linux-mm , LKML , nfont@linux.vnet.ibm.com, KAMEZAWA Hiroyuki , Greg KH On Mon, 10 Oct 2011 08:11:19 +0100 Mel Gorman wrote: > It is expected that memory being brought online is PageReserved > similar to what happens when the page allocator is being brought up. > Memory is onlined in "memory blocks" which consist of one or more > sections. Unfortunately, the code that verifies PageReserved is > currently assuming that the memmap backing all these pages is virtually > contiguous which is only the case when CONFIG_SPARSEMEM_VMEMMAP is set. > As a result, memory hot-add is failing on !VMEMMAP configurations > with the message; > > kernel: section number XXX page number 256 not reserved, was it already online? > > This patch updates the PageReserved check to lookup struct page once > per section to guarantee the correct struct page is being checked. > Nathan's earlier version of this patch is already in linux-next, via Greg. We should drop the old version and get the new one merged instead. -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org