Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755633AbXFWKYP (ORCPT ); Sat, 23 Jun 2007 06:24:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752369AbXFWKYA (ORCPT ); Sat, 23 Jun 2007 06:24:00 -0400 Received: from mtagate7.uk.ibm.com ([195.212.29.140]:19620 "EHLO mtagate7.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752111AbXFWKX7 (ORCPT ); Sat, 23 Jun 2007 06:23:59 -0400 Date: Fri, 22 Jun 2007 17:35:30 -0700 From: Muli Ben-Yehuda To: Yinghai Lu Cc: Andi Kleen , Alan Cox , "Eric W. Biederman" , Andrew Morton , Vivek Goyal , Linux Kernel Mailing List Subject: Re: [PATCH] x86-64: disable the GART before allocate aperture Message-ID: <20070623003530.GA4505@rhun.smartcity.com> References: <200706221219.16243.yinghai.lu@sun.com> <20070622231951.4d516215@the-village.bc.nu> <200706230214.02535.ak@suse.de> <467C6906.6020105@sun.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <467C6906.6020105@sun.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1437 Lines: 34 On Fri, Jun 22, 2007 at 05:27:50PM -0700, Yinghai Lu wrote: > Andi Kleen wrote: > >On Saturday 23 June 2007 00:19:51 Alan Cox wrote: > >The kdump kernel should be normally all <4GB anyways. You won't > >need any IOMMU for its IO unless you O_DIRECT/sendfile out of /proc/kcore. > >Just don't do that (but I suspect it won't work anyways) > > > >If it's not then swiotlb will also not work because it won't get > >any memory <4GB. > > > >But I doubt this was YH's problem - the panic kernel memory > >is always reserved and there shouldn't be any ongoing DMAs in this > >area anyways. And what happens outside the kdump kernel shouldn't matter. > > > >I suspect he rather saw problems with non kdump kexec where we > >can just shut down the GART properly beforehand. > > current I only test kexec only. So clean shut GART in first kernel will > help. > > where is hook for shutdown? add one in dma_ops? I was wondering the same thing. I think it should hook into the standard device model. It definitely should *not* be in the dma_ops (it has nothing to do with DMA...) - if needed for this or something else we should add a struct iommu_ops which includes a dma_ops member. Cheers, Muli - 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/