Messages in this thread | | | Subject | RE: Can Linux live without DMA zone? | From | Peter Zijlstra <> | Date | Thu, 02 Nov 2006 08:13:11 +0100 |
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On Thu, 2006-11-02 at 11:43 +0800, Conke Hu wrote: > It seems a good idea. > Is dma zone is still necessay on most modern computers?
(don't top post!)
if you would have used google, you'd have found this: http://www.mail-archive.com/linux-arch@vger.kernel.org/msg01623.html
cheers
> -----Original Message----- > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of Jun Sun > Sent: 2006年11月2日 10:16 > To: linux-kernel@vger.kernel.org > Subject: Can Linux live without DMA zone? > > > I am trying to reserve a block of memory (>16MB) starting from 0 and hide it > from kernel. A consequence is that DMA zone now has size 0. That causes > many drivers to grief (OOMs). > > I see two ways out: > > 1. Modify individual drivers and convince them not to alloc with GFP_DMA. > I have been trying to do this but do not seem to see an end of it. :) > > 2. Simply lie and increase MAX_DMA_ADDRESS to really big (like 1GB) so that > the whole memory region belongs to DMA zone. > > #2 sounds pretty hackish. I am sure something bad will happen > sooner or later (like what?). But so far it appears to be working fine. > > The fundamental question is: Has anybody tried to run Linux without 0 sized > DMA zone before? Am I doing something that nobody has done before (which is > something really hard to believe these days with Linux :P)? > > Cheers. > > Jun > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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