From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964876AbWFSUI6 (ORCPT ); Mon, 19 Jun 2006 16:08:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964878AbWFSUI6 (ORCPT ); Mon, 19 Jun 2006 16:08:58 -0400 Received: from mailgw.aecom.yu.edu ([129.98.1.16]:39091 "EHLO mailgw.aecom.yu.edu") by vger.kernel.org with ESMTP id S964876AbWFSUI5 (ORCPT ); Mon, 19 Jun 2006 16:08:57 -0400 Mime-Version: 1.0 Message-Id: In-Reply-To: <200606161031.16554.ak@suse.de> References: <200606161031.16554.ak@suse.de> Date: Mon, 19 Jun 2006 16:09:02 -0400 To: Andi Kleen From: Maurice Volaski Subject: Re: The "Out of IOMMU space" error and the "Please enable the IOMMU option" option Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org With 2.6.16.20 and iommu=memaper=4, Jun 19 15:20:31 [kernel] [ 103.697664] PCI-DMA: Disabling AGP. Jun 19 15:20:31 [kernel] [ 103.698226] PCI-DMA: using GART IOMMU. Jun 19 15:20:31 [kernel] [ 103.698341] PCI-DMA: Reserving 512MB of IOMMU area in the AGP aperture I'm not sure why it tells me it's disabling AGP, but otherwise it looks good. >On Thursday 15 June 2006 23:17, Maurice Volaski wrote: >> Occasionally, we get errors like these: >> >> Jun 9 00:56:35 [kernel] [18020.416620] PCI-DMA: Out of IOMMU space >> for 12288 bytes at device 0000:03:01.0 > > >> and it looks like it might have something to do with these messages >> (after updating and setting BIOS as below): >> >> Jun 15 16:38:54 [kernel] [ 0.000000] Checking aperture... >> Jun 15 16:38:54 [kernel] [ 0.000000] CPU 0: aperture @ 0 size 256 MB >> Jun 15 16:38:54 [kernel] [ 0.000000] No AGP bridge found >> Jun 15 16:38:54 [kernel] [ 0.000000] Your BIOS doesn't leave a >> aperture memory hole >> Jun 15 16:38:54 [kernel] [ 0.000000] Please enable the IOMMU >> option in the BIOS setup >> Jun 15 16:38:54 [kernel] [ 0.000000] This costs you 64 MB of RAM >> Jun 15 16:38:54 [kernel] [ 0.000000] Mapping aperture over 65536 >> KB of RAM @ 8000000 >> >> The box is a dual Opteron 250 with an Arima HDAMA Rev. D motherboard. > >Not directly - the kernel will create a fallback aperture if it can't >find one provided by the BIOS. The default is 64MB, but it can be >enlarged with iommu=memaper=4 > >There was also a bug that might have caused this over longer uptimes. >If you still see it with latest 2.6.16.stable (19 or so). > >If it still happens with those two changes then something is likely >leaking mappings or your have a extreme workload that needs >a lot of mappings. > > >> First, am I correct to assume that I'm not getting the 256 MB? > >Yes you'll get 64MB fallback likely. > >> >> Second, is the the case the BIOS is lying? > >Probably yes. > >-Andi -- Maurice Volaski, mvolaski@aecom.yu.edu Computing Support, Rose F. Kennedy Center Albert Einstein College of Medicine of Yeshiva University