From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] introduce config option to disable DMA zone on i386 From: Arjan van de Ven In-Reply-To: <20061228170302.GA4335@dmt> References: <20061228170302.GA4335@dmt> Content-Type: text/plain Date: Thu, 28 Dec 2006 18:43:03 +0100 Message-Id: <1167327784.3281.4341.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, olpc-devel@laptop.org List-ID: On Thu, 2006-12-28 at 15:03 -0200, Marcelo Tosatti wrote: > Hi, > > The following patch adds a config option to get rid of the DMA zone on i386. > > Architectures with devices that have no addressing limitations (eg. PPC) > already work this way. > > This is useful for custom kernel builds where the developer is certain that > there are no address limitations. > > For example, the OLPC machine contains: > > - USB devices > - no floppy > - no address limited PCI devices > - no floppy > > A unified zone simplifies VM reclaiming work, and also simplifies OOM > killer heuristics (no need to deal with OOM on the DMA zone). > > Comments? Hi, since one gets random corruption if a user gets this wrong, at least make things like floppy and all CONFIG_ISA stuff conflict with this option.... without that your patch feels like a walking time bomb... (and please include all PCI drivers that only can do 24 bit or 28bit or .. non-32bit dma as well) Greetings, Arjan van de Ven -- 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