From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754587Ab3AKOvF (ORCPT ); Fri, 11 Jan 2013 09:51:05 -0500 Received: from 8bytes.org ([85.214.48.195]:57681 "EHLO mail.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753860Ab3AKOvE (ORCPT ); Fri, 11 Jan 2013 09:51:04 -0500 Date: Fri, 11 Jan 2013 15:50:59 +0100 From: Joerg Roedel To: Shuah Khan Cc: Alexey Kardashevskiy , Joerg Roedel , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Shuah Khan Subject: Re: [PATCH] iommu: moving initialization earlier Message-ID: <20130111145059.GJ25591@8bytes.org> References: <1357545112-17375-1-git-send-email-aik@ozlabs.ru> <20130110170941.GA2556@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-DSPAM-Result: Whitelisted X-DSPAM-Processed: Fri Jan 11 15:51:01 2013 X-DSPAM-Confidence: 0.9989 X-DSPAM-Probability: 0.0000 X-DSPAM-Signature: 50f026d522971019351938 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 10, 2013 at 01:40:17PM -0700, Shuah Khan wrote: > I am currently debugging IO_PAGE_FAULTS on 3.6.11 (happens on all > pre-3.7 releases). I root-caused the reason 3.7 works is because in > 3.7 amd iommu driver moving up the early iommu initialization from > irq_remap_ops with the irq remapping feature. Have you investigated the reason for those IO_PAGE_FAULTS? I guess they come from the USB controlers and happen between the time the IOMMU is enabled and the USB controlers are taken over by the Linux kernel from the BIOS. But I don't see why this patch can have any impact on the IO_PAGE_FAULTS you are seeing. Joerg