From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DC4EC28CC5 for ; Wed, 5 Jun 2019 13:57:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CA8A20693 for ; Wed, 5 Jun 2019 13:57:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728052AbfFEN5t (ORCPT ); Wed, 5 Jun 2019 09:57:49 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:58340 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727904AbfFEN5t (ORCPT ); Wed, 5 Jun 2019 09:57:49 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x55DlXIT134053 for ; Wed, 5 Jun 2019 09:57:48 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sxemyh8b1-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 05 Jun 2019 09:57:47 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 5 Jun 2019 14:57:43 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x55DvgnK60358766 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 5 Jun 2019 13:57:42 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 39AADA405B; Wed, 5 Jun 2019 13:57:42 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EEA1FA4054; Wed, 5 Jun 2019 13:57:41 +0000 (GMT) Received: from dyn-9-152-212-90.boeblingen.de.ibm.com (unknown [9.152.212.90]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Wed, 5 Jun 2019 13:57:41 +0000 (GMT) Date: Wed, 5 Jun 2019 15:57:41 +0200 (CEST) From: Sebastian Ott X-X-Sender: sebott@schleppi To: Christoph Hellwig cc: Ming Lei , Hannes Reinecke , Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: too large sg segments with commit 09324d32d2a08 In-Reply-To: <20190605133002.GA13368@lst.de> References: <20190605100928.GA9828@lst.de> <20190605133002.GA13368@lst.de> User-Agent: Alpine 2.21 (LFD 202 2017-01-01) Organization: =?ISO-8859-15?Q?=22IBM_Deutschland_Research_&_Development_GmbH?= =?ISO-8859-15?Q?_=2F_Vorsitzende_des_Aufsichtsrats=3A_Matthias?= =?ISO-8859-15?Q?_Hartmann_Gesch=E4ftsf=FChrung=3A_Dirk_Wittkopp?= =?ISO-8859-15?Q?_Sitz_der_Gesellschaft=3A_B=F6blingen_=2F_Reg?= =?ISO-8859-15?Q?istergericht=3A_Amtsgericht_Stuttgart=2C_HRB_2432?= =?ISO-8859-15?Q?94=22?= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-TM-AS-GCONF: 00 x-cbid: 19060513-0028-0000-0000-000003765F67 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19060513-0029-0000-0000-000024363B7C Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-05_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=873 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906050088 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, 5 Jun 2019, Christoph Hellwig wrote: > Actually, it looks like something completely general isn't > easily doable, not without some major dma API work. Here is what > should fix nvme, but a few other drivers will need fixes as well: > > --- > From 745541130409bc837a3416300f529b16eded8513 Mon Sep 17 00:00:00 2001 > From: Christoph Hellwig > Date: Wed, 5 Jun 2019 14:55:26 +0200 > Subject: nvme-pci: don't limit DMA segement size > > NVMe uses PRPs (or optionally unlimited SGLs) for data transfers and > has no specific limit for a single DMA segement. Limiting the size > will cause problems because the block layer assumes PRP-ish devices > using a virt boundary mask don't have a segment limit. And while this > is true, we also really need to tell the DMA mapping layer about it, > otherwise dma-debug will trip over it. > > Signed-off-by: Christoph Hellwig > Reported-by: Sebastian Ott Works for me. Thanks!