From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 14 Aug 2007 12:43:56 -0700 From: Andy Isaacson Subject: Re: [PATCH 3/4] Embed zone_id information within the zonelist->zones pointer Message-ID: <20070814194356.GL21492@hexapodia.org> References: <20070813230801.GH3406@bingen.suse.de> <20070813234322.GJ3406@bingen.suse.de> <20070814000041.GL3406@bingen.suse.de> <20070814002223.2d8d42c5@the-village.bc.nu> <20070814001441.GN3406@bingen.suse.de> <20070814191158.GB14093@hexapodia.org> <20070814202350.GT3406@bingen.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070814202350.GT3406@bingen.suse.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: Alan Cox , Christoph Lameter , Mel Gorman , Lee.Schermerhorn@hp.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-mips@linux-mips.org List-ID: On Tue, Aug 14, 2007 at 10:23:51PM +0200, Andi Kleen wrote: > > bcm43xx hardware does show up on low-end MIPS boxes (wrt54g anybody?) > > that would be sorely hurt by excess copies. > > Lowend boxes don't have more than 1GB of RAM. With <= 1GB you don't > need to copy on bcm43xx. OK, that makes sense and is reassuring, but note that some MIPS boxes have only part of their physical memory below 1GB; IIRC the BCM4704/BCM5836 supports up to 512MB of physical memory, with 256MB in the first GB and the second 256MB located above the 1GB line. (But it's been a while since I've run such a machine, so I could be misremembering the sizes and offsets.) Yeah, if you stick a PCI chip with a 30-bit PCI DMA mask into a machine with memory above 1GB, then copying has to happen. Unless the memory allocator can avoid returning memory in the un-dma-able region... -andy -- 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