From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [rfc][patch 0/3] bootmem2: a memory block-oriented boot time allocator References: <20080505095938.326928514@symbol.fehenstaub.lan> Date: Mon, 05 May 2008 13:23:30 +0200 In-Reply-To: <20080505095938.326928514@symbol.fehenstaub.lan> (Johannes Weiner's message of "Mon, 05 May 2008 11:59:38 +0200") Message-ID: <87ve1touz1.fsf@saeurebad.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Ingo Molnar , Andi Kleen , Yinghai Lu , Andrew Morton , Linus Torvalds , Yasunori Goto List-ID: Hi, Johannes Weiner writes: > The problem is that memory nodes are not anymore garuanteed to be > linear on certain configurations, they may overlap each other and a > node might span page ranges that are not physically residing on it. > > Note that this is in no way theoretical only, bootmem suffers from > this fact right now: A pfn range has to be operated on on every node > that holds it (because a PFN is not unique anymore) and bootmem can > not garuantee that the memory allocated from a specific node actually > resides on that node. > > For example: > > node 0: 0-2G, 4-6G > node 1: 2-4G, 6-8G > > Bootmem currently sees the 2-4G range twice (and has to operate on > both node's bitmaps) and if memory is allocated on node 1, it may > return memory that is between the 2-4G range and actually resides on > node 0. Uh, mixup. The memory resides on node 1 but may get allocated from node 0. Hannes -- 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