From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout2.freenet.de ([195.4.92.92]:47715 "EHLO mout2.freenet.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754288AbbHGGG2 (ORCPT ); Fri, 7 Aug 2015 02:06:28 -0400 Subject: Re: AMD-Vi IO_PAGE_FAULTs and ata3.00: failed command: READ FPDMA QUEUED errors since Linux 4.0 To: Andreas Hartmann , Jeff Moyer , Mike Snitzer References: <55B7BEA2.30205@01019freenet.de> <20150728175054.GB24782@redhat.com> <55B7D054.4070308@maya.org> <20150728192908.GA25264@redhat.com> <55BCD5A7.2080708@maya.org> <55BE1D5E.6020709@maya.org> <55BE65E6.7060901@maya.org> <20150803081249.GF14980@8bytes.org> <20150804144711.GB24716@redhat.com> <55C10069.6060303@maya.org> Cc: Joerg Roedel , linux-pci , device-mapper development , Jens Axboe , iommu@lists.linux-foundation.org, Leo Duran , Mikulas Patocka , Christoph Hellwig , Milan Broz , linux-ide@vger.kernel.org From: Andreas Hartmann Message-ID: <55C44A52.2090208@maya.org> Date: Fri, 7 Aug 2015 08:04:02 +0200 MIME-Version: 1.0 In-Reply-To: <55C10069.6060303@maya.org> Content-Type: text/plain; charset=iso-8859-15 Sender: linux-pci-owner@vger.kernel.org List-ID: On 08/04/2015 at 08:11 PM, Andreas Hartmann wrote: > On 08/04/2015 at 06:10 PM Jeff Moyer wrote: >> Mike Snitzer writes: >> >>> On Mon, Aug 03 2015 at 4:12am -0400, >>> Joerg Roedel wrote: >>> >>>> On Sun, Aug 02, 2015 at 08:48:06PM +0200, Andreas Hartmann wrote: >>>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=34b48db66e08ca1c1bc07cf305d672ac940268dc >>>>>>> >>>>>>> block: remove artifical max_hw_sectors cap >>>> >>>> Looking at the patch, it seems to me that it just uncovered a bug >>>> elsewhere. It looks like an underlying driver doesn't expect the >>>> big io-requests that the patch enables and does not dma-map the whole >>>> target buffer, causing the IO_PAGE_FAULTs later. >>> >>> That patch has caused issues elsewhere too, see this 'Revert "block: >>> remove artifical max_hw_sectors cap"' thread (if/when lkml.org >>> cooperates): https://lkml.org/lkml/2015/7/20/572 >>> >>> But it could be that there is a need for a horkage fix for this specific >>> hardware? something comparable to this?: >>> http://git.kernel.org/linus/af34d637637eabaf49406eb35c948cd51ba262a6 >>> >>> We are running out of time to fix these whack-a-mole issues in 4.2 >>> though. >> >> CC-ing linux-ide. Original dm-devel posting: >> https://www.redhat.com/archives/dm-devel/2015-July/msg00178.html >> >> Andreas, I would be curious to know what the value of >> /sys/block/sdX/queue/max_hw_sectors_kb is for the affected disks. > > > It's always 32767. > > Where does this value come from? Is it empirical or is it calculated (on > base of which parameters)? > > > Devices are: > > 1 x Corsair Force GT (SSD) > 2 x ST3000DM001-1CH166 (rotational) (WD) > > > How can I set a higher max_sectors_kb on boot before the partitions are > mounted (-> as kernel option)? Mounting the partitions here (w/ systemd) > is the easiest and best way to trigger the problem! Please - no idea how to set higher max_sectors_kb before mounting of partitions? Come on! I want to test exactly this situation! Regards, Andreas