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_PASS,URIBL_BLOCKED autolearn=unavailable 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 07DE9C43381 for ; Thu, 28 Feb 2019 12:34:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2B9E2083D for ; Thu, 28 Feb 2019 12:34:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731635AbfB1Mev (ORCPT ); Thu, 28 Feb 2019 07:34:51 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59580 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725918AbfB1Meu (ORCPT ); Thu, 28 Feb 2019 07:34:50 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1SCU9Xw007469 for ; Thu, 28 Feb 2019 07:34:49 -0500 Received: from e14.ny.us.ibm.com (e14.ny.us.ibm.com [129.33.205.204]) by mx0b-001b2d01.pphosted.com with ESMTP id 2qxe7s4njc-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 28 Feb 2019 07:34:49 -0500 Received: from localhost by e14.ny.us.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) Thu, 28 Feb 2019 12:34:45 -0000 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1SCYi8j23068792 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 28 Feb 2019 12:34:44 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3D531B2066; Thu, 28 Feb 2019 12:34:44 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 55412B2065; Thu, 28 Feb 2019 12:34:41 +0000 (GMT) Received: from [9.199.36.171] (unknown [9.199.36.171]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 28 Feb 2019 12:34:40 +0000 (GMT) Subject: Re: [PATCH 1/2] fs/dax: deposit pagetable even when installing zero page To: Jan Kara Cc: akpm@linux-foundation.org, "Kirill A . Shutemov" , mpe@ellerman.id.au, Ross Zwisler , "Oliver O'Halloran" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: <20190228083522.8189-1-aneesh.kumar@linux.ibm.com> <20190228092101.GA22210@quack2.suse.cz> From: "Aneesh Kumar K.V" Date: Thu, 28 Feb 2019 18:04:24 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190228092101.GA22210@quack2.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19022812-0052-0000-0000-00000392380D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010679; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000281; SDB=6.01167573; UDB=6.00609978; IPR=6.00948186; MB=3.00025780; MTD=3.00000008; XFM=3.00000015; UTC=2019-02-28 12:34:47 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022812-0053-0000-0000-00005FFF6498 Message-Id: <5c788802-bbf4-2c12-b126-d9b83eea86d5@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-28_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902280087 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/28/19 2:51 PM, Jan Kara wrote: > On Thu 28-02-19 14:05:21, Aneesh Kumar K.V wrote: >> Architectures like ppc64 use the deposited page table to store hardware >> page table slot information. Make sure we deposit a page table when >> using zero page at the pmd level for hash. >> >> Without this we hit >> >> Unable to handle kernel paging request for data at address 0x00000000 >> Faulting instruction address: 0xc000000000082a74 >> Oops: Kernel access of bad area, sig: 11 [#1] >> .... >> >> NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 >> LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 >> Call Trace: >> hash_page_mm+0x43c/0x740 >> do_hash_page+0x2c/0x3c >> copy_from_iter_flushcache+0xa4/0x4a0 >> pmem_copy_from_iter+0x2c/0x50 [nd_pmem] >> dax_copy_from_iter+0x40/0x70 >> dax_iomap_actor+0x134/0x360 >> iomap_apply+0xfc/0x1b0 >> dax_iomap_rw+0xac/0x130 >> ext4_file_write_iter+0x254/0x460 [ext4] >> __vfs_write+0x120/0x1e0 >> vfs_write+0xd8/0x220 >> SyS_write+0x6c/0x110 >> system_call+0x3c/0x130 >> >> Signed-off-by: Aneesh Kumar K.V > > Thanks for the patch. It looks good to me. You can add: > > Reviewed-by: Jan Kara > >> --- >> TODO: >> * Add fixes tag > > Probably this is a problem since initial PPC PMEM support, isn't it? > Considering ppc64 is the only broken architecture here, I guess I will use the commit that enabled PPC PMEM support here. -aneesh