Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 7 Dec 2022 14:27:52 -0800
From:   Mike Kravetz <mike.kravetz@oracle.com>
To:     Peter Xu <peterx@redhat.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Jann Horn <jannh@google.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        James Houghton <jthoughton@google.com>,
        Rik van Riel <riel@surriel.com>,
        Miaohe Lin <linmiaohe@huawei.com>,
        Nadav Amit <nadav.amit@gmail.com>,
        John Hubbard <jhubbard@nvidia.com>,
        David Hildenbrand <david@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Muchun Song <songmuchun@bytedance.com>
Subject: Re: [PATCH v2 09/10] mm/hugetlb: Introduce hugetlb_walk()
Message-ID: <Y5ETaE2dEUP78l6Y@monkey>
References: <20221207203034.650899-1-peterx@redhat.com>
 <20221207203156.651077-1-peterx@redhat.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20221207203156.651077-1-peterx@redhat.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?m6Vdew3KlS1wGPJ5gSIaQ81GrhIQWoKjFa+U2ZJMnwyUSTOAVXmJC1Fnev28?=
 =?us-ascii?Q?5qQ/K0QqBAR5JNT1gvQQCmII0DaoBeFE+1MQXXpD7U7E0Z8FJKZWs99iZEdO?=
 =?us-ascii?Q?oExTIvmolWJF5ts7eeRpMiRVPUuu/qenfsHGuqN1xku9C5PhQUi47yR3OYw+?=
 =?us-ascii?Q?53eF5wB/XPtpVVWeVDRqGThZtQ8jV15U9t6+3ELpFwNpQyc/6ed0je6ihiFh?=
 =?us-ascii?Q?O1IaBaoD46YdepiIL+GoCdyuVEkJ1Gk8lNdJtb8L4tDgtctZcaz4uG49AljE?=
 =?us-ascii?Q?Vo5WWOZQRtp8CguxgBdmgzYbRMXVGDIjeflYys3W+wCpXritehrsYSUwLggD?=
 =?us-ascii?Q?gTG6gDkKfi2x/hPvXwNCrA3uhCcWSaNAd6EWdAWDGmhnhX7L6B34E23zsJPn?=
 =?us-ascii?Q?HyoPLttCfwPlvDZ5qqReojGprshrA4HBq/UA8+3TM25hFyzHbh92Lc7v0enG?=
 =?us-ascii?Q?tR3tExPFxWbC50G/7+1NtpPW6vqHlh9fwYPU+rtN3l0TSobKwnoXW9D5AwZ2?=
 =?us-ascii?Q?2HKQi/epKLElgRTvZYIThSe8S9QOAFQfyIl1RZFj8OivJnrLlvXQf+wSrdbR?=
 =?us-ascii?Q?p3sN7wCrjGhojE2cvuWuYgCHY4VzILnbw+abIBMgV0/rIFycXQ6ly6FhdcCf?=
 =?us-ascii?Q?yeW7jrkMv6BzLiwnfvy1UNkKPxw5Tmur1PUQi07VXbsV3JUYPEqDdWd/+oJo?=
 =?us-ascii?Q?V4o0Lr84TCxwp8/9DusW0AcYtoQLYImzrvDRe8lmAyknd3RoualeV0Qq063a?=
 =?us-ascii?Q?3q5we4RBaZLAoj1acAJJF8rdeRfgd/1vb2IAISUcedrSqsfDQX13TVf0FRqs?=
 =?us-ascii?Q?H4PTT7PbD0aT/gi2eC5fcT6cFZ2X3Z+u8361ngOKOUNWNnW5LStx3MkEJgz2?=
 =?us-ascii?Q?w5klAQ0uVWAr8oY7mIZGlJsDCizawDo+xjhOXtW7HEnt/VjfOdMWqNVwVTlR?=
 =?us-ascii?Q?EzU56srUulwGYQP3kR64bC2+7BC6WB/g3euzl5tTIkox6uXfoo5+c4nMDiL+?=
 =?us-ascii?Q?y7+cDyt/9w3+Fuqhi32blmnyoKIjLDQ8ZZBGUt1PRqmCjLodUR5d76bZlA3d?=
 =?us-ascii?Q?PHlzed7Jh6U0SB8T3eKVJr/UQiNf1C/6gVEHL15ERfLdPNM8plagOxShE/LD?=
 =?us-ascii?Q?k1NjXQMZIKuIB63cVMKoCysvbuiVSVAOsBEeW977IP3zlbgc+ZdOWiuPgoNu?=
 =?us-ascii?Q?xjL2wB+CoaxaWXB5L2+oA2YtuC+jrUpGPmY9CmZvTYLg8LD5rMbEOodxaASm?=
 =?us-ascii?Q?53u6VbvVA6QN15FhwLs/gYcSQPUsnIXWP0rxrcm7rBBh8TGYPXt4trfAlkNU?=
 =?us-ascii?Q?eAHdRTwglQdyaQaZqf5Woh2/8hW7h3XHsn1s0PDeSCaRsQfYesym9AJgsYjW?=
 =?us-ascii?Q?GGDubUOe+QoAr6euzrBQDuyMVR2zIZncS+bdDKXAHsXE1FhLmFMD4eoMgGKR?=
 =?us-ascii?Q?jGlYb0FhXCSk3Taz28LlvVU3SeW/VaiVZeEpaDRyiPDOPPrikwcLLFb+yf1u?=
 =?us-ascii?Q?qqAvJsJ5wuna2/BPelueRtEdrtp/MDNTnAI70OtPndtak3nWh0LiqmpBEgJy?=
 =?us-ascii?Q?H4oq6eFrEjLpfQ8EzNFKeone6fqcoh1F1s1HbmRJn4igsAIuA1SObRPaJhF3?=
 =?us-ascii?Q?5A=3D=3D?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: c4b4f3b0-ed25-43c2-9245-08dad8a24984
X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Dec 2022 22:27:55.7166
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: ZTW9Q97LIvRNPv/tehBd01jyc7bQUYntGjuYAsWoqyyy3tYqd2QzMkyP099PSWd8PxYLa8dWZBqQAY9o6WksRg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BLAPR10MB5329
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.205,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1
 definitions=2022-12-07_11,2022-12-07_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 spamscore=0 adultscore=0
 suspectscore=0 mlxlogscore=999 malwarescore=0 phishscore=0 bulkscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000
 definitions=main-2212070190
X-Proofpoint-ORIG-GUID: YfGjvxUCpEk8KG7MAbvdV5BEs1-zLTCi
X-Proofpoint-GUID: YfGjvxUCpEk8KG7MAbvdV5BEs1-zLTCi
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 12/07/22 15:31, Peter Xu wrote:
> huge_pte_offset() is the main walker function for hugetlb pgtables.  The
> name is not really representing what it does, though.
> 
> Instead of renaming it, introduce a wrapper function called hugetlb_walk()
> which will use huge_pte_offset() inside.  Assert on the locks when walking
> the pgtable.
> 
> Note, the vma lock assertion will be a no-op for private mappings.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  fs/hugetlbfs/inode.c    |  4 +---
>  fs/userfaultfd.c        |  6 ++----
>  include/linux/hugetlb.h | 39 +++++++++++++++++++++++++++++++++++++++
>  mm/hugetlb.c            | 32 +++++++++++++-------------------
>  mm/page_vma_mapped.c    |  2 +-
>  mm/pagewalk.c           |  4 +---
>  6 files changed, 57 insertions(+), 30 deletions(-)

Thanks!  I like the lockdep checks in hugetlb_walk.

Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>

-- 
Mike Kravetz