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=-5.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 220DCC433E0 for ; Wed, 24 Feb 2021 16:55:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7B87564F07 for ; Wed, 24 Feb 2021 16:55:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B87564F07 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EC21A6B0006; Wed, 24 Feb 2021 11:55:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E4BE06B006C; Wed, 24 Feb 2021 11:55:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D14FA6B0070; Wed, 24 Feb 2021 11:55:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id B3D016B0006 for ; Wed, 24 Feb 2021 11:55:36 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 594D0180ACF76 for ; Wed, 24 Feb 2021 16:55:36 +0000 (UTC) X-FDA: 77853762672.12.F99A53B Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf02.hostedemail.com (Postfix) with ESMTP id A6F544080F74 for ; Wed, 24 Feb 2021 16:55:20 +0000 (UTC) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 11OGZCsL146530; Wed, 24 Feb 2021 11:55:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=pp1; bh=AmVyFiDlcXmNzyd+x5VKFRhFShv0SsXZhacZ0vpQhTA=; b=aQqLJeFq9VbwKsKLv3RwktG/BUNNgD880jb23SXrVZhLNRJnFvT+mA/IIdK8nkPiKR3W rd/RUrS4HiRQRD79ms3CA/WeHjZVwLFJYGLwb47QpwIzDatoxW+2CgUW4G0ZVjPvi9Mq 4qZuHfoKgPXGub1EPKfzsf+/joxeDlUuVkqytzCWLLBQ4KkwpzBHGnbkEGmWzrqYYp+m JwMBhrpoL2JoxhriODMWwL/PyUgUYTUeZpzzgL8k+h9YYGLQLUDr3RwMjdDmLL2KTxdM DBE60FwSe3wLnxcnq11eo/cSwchFSAPlvIzrKyoF5hvIrFcm7vBk+mF/bMgjdYJsyNti xA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 36wmfwdrdv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 24 Feb 2021 11:55:28 -0500 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 11OGZYDE149680; Wed, 24 Feb 2021 11:55:27 -0500 Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 36wmfwdrcs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 24 Feb 2021 11:55:27 -0500 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 11OGq8ll023939; Wed, 24 Feb 2021 16:55:25 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma03ams.nl.ibm.com with ESMTP id 36tt283qns-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 24 Feb 2021 16:55:25 +0000 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 11OGt9ZZ27525480 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 24 Feb 2021 16:55:09 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3356742054; Wed, 24 Feb 2021 16:55:22 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 912A34204F; Wed, 24 Feb 2021 16:55:21 +0000 (GMT) Received: from thinkpad (unknown [9.171.7.180]) by d06av24.portsmouth.uk.ibm.com (Postfix) with SMTP; Wed, 24 Feb 2021 16:55:21 +0000 (GMT) Date: Wed, 24 Feb 2021 17:55:20 +0100 From: Gerald Schaefer To: Peter Xu Cc: Mike Kravetz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, shu wang , Axel Rasmussen , Andrea Arcangeli , Heiko Carstens , Alexey Dobriyan , Matthew Wilcox , Michel Lespinasse , Andrew Morton Subject: Re: [RFC PATCH 1/5] hugetlb: add hugetlb helpers for soft dirty support Message-ID: <20210224175520.76ba0e68@thinkpad> In-Reply-To: <20210224174608.7c9ca5ed@thinkpad> References: <20210211000322.159437-1-mike.kravetz@oracle.com> <20210211000322.159437-2-mike.kravetz@oracle.com> <20210217162415.GA6519@xz-x1> <20210224174608.7c9ca5ed@thinkpad> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-02-24_06:2021-02-24,2021-02-24 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 impostorscore=0 mlxlogscore=999 clxscore=1015 adultscore=0 malwarescore=0 lowpriorityscore=0 phishscore=0 mlxscore=0 spamscore=0 bulkscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2102240127 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: A6F544080F74 X-Stat-Signature: i8x8p73wfiskb1aookafejjkcqjpu553 Received-SPF: none (linux.ibm.com>: No applicable sender policy available) receiver=imf02; identity=mailfrom; envelope-from=""; helo=mx0a-001b2d01.pphosted.com; client-ip=148.163.156.1 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614185720-767533 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 24 Feb 2021 17:46:08 +0100 Gerald Schaefer wrote: [...] > Then we fundamentally changed the way how we deal with that "hugetlb code > is treating pmds as ptes" issue. Instead of caring about that in all > huge_pte_xxx primitives, huge_ptep_get() will now return a nicely faked pte > for s390, i.e. something that looks like a pte would look like, and not the > real pmd/pud value. With that, hugetlb code can do all its pte handling on > that fake pte, and the conversion back to a proper pmd/pud is done in > set_huge_pte(). BTW, in case anybody is wondering, this conversion from and to pmd for s390 will also care about the soft dirty bit, even though it was not really used before for hugetlb. So Mikes approach to add the default primitives for s390 should work fine.