From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f52.google.com (mail-pa0-f52.google.com [209.85.220.52]) by kanga.kvack.org (Postfix) with ESMTP id EDFEC6B0031 for ; Mon, 18 Nov 2013 20:32:41 -0500 (EST) Received: by mail-pa0-f52.google.com with SMTP id ld10so2992008pab.39 for ; Mon, 18 Nov 2013 17:32:41 -0800 (PST) Received: from psmtp.com ([74.125.245.155]) by mx.google.com with SMTP id ty3si6140654pbc.347.2013.11.18.17.32.39 for ; Mon, 18 Nov 2013 17:32:40 -0800 (PST) Message-ID: <528ABFA3.6060905@zytor.com> Date: Mon, 18 Nov 2013 17:32:19 -0800 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [PATCH 0/3] Early use of boot service memory References: <20131114180455.GA32212@anatevka.fc.hp.com> <20131115005049.GJ5116@anatevka.fc.hp.com> <20131115062417.GB9237@gmail.com> <5285C639.5040203@zytor.com> <20131115140738.GB6637@redhat.com> <52865CA1.5020309@zytor.com> <20131115183002.GE6637@redhat.com> In-Reply-To: <20131115183002.GE6637@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vivek Goyal Cc: Yinghai Lu , Ingo Molnar , jerry.hoemann@hp.com, Pekka Enberg , Rob Landley , Thomas Gleixner , Ingo Molnar , x86 maintainers , Matt Fleming , Andrew Morton , "list@ebiederm.org:DOCUMENTATION" , "list@ebiederm.org:MEMORY MANAGEMENT" , linux-efi@vger.kernel.org, LKML On 11/15/2013 10:30 AM, Vivek Goyal wrote: > > And IOMMU support is very flaky with kdump. And IOMMU's can be turned > off at command line. And that would force one to remove crahkernel_low=0. > So change of one command line option forces change of another. It is > complicated. > > Also there are very few systems which work with IOMMU on. A lot more > which work without IOMMU. We have all these DMAR issues and still nobody > has been able to address IOMMU issues properly. > Why do we need such a big bounce buffer for kdump swiotlb anyway? Surely the vast majority of all dump devices don't need it, so it is there for completeness, no? -hpa -- 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