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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25574C433FE for ; Wed, 2 Feb 2022 18:28:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 431D28D0117; Wed, 2 Feb 2022 13:28:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3E0A48D0114; Wed, 2 Feb 2022 13:28:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2CFF18D0117; Wed, 2 Feb 2022 13:28:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0165.hostedemail.com [216.40.44.165]) by kanga.kvack.org (Postfix) with ESMTP id 1B88A8D0114 for ; Wed, 2 Feb 2022 13:28:50 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C977B97916 for ; Wed, 2 Feb 2022 18:28:49 +0000 (UTC) X-FDA: 79098675978.15.C728DBA Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf16.hostedemail.com (Postfix) with ESMTP id 15EA9180005 for ; Wed, 2 Feb 2022 18:28:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=DHt+NoiQ/xSDzcu85V4cS/XqDEmzCog6ySkjKbfn9Y4=; b=Pc3z+/fGMsWFz6LsSLIIQE5noH /S4+fwoYEH0STHqc5Vh9NnnAMQBL07imdXuFR+SlwylTbKodsNxhP1pZb3tp5bCXn19LzDITTKcxB cQlQhPLSrCxeywyWBe+ajFd4uB40UM3qdNMAPxmMDdvinodcuT+Ht9LsP5DYBK81MYUEaxV6oRQc4 cNRR7p3wDwukXXid0UOM8DAEOUHQuQapC60F0vFAdw/vJyYkW1FjqtG4SxJXbUOrMRNYS/OdXxHNX r/94W6wRKoMP0UBjr26/YURhqnOfzagiNzzKT4gm1is+U63mxHPiwfmxyp6IyE0EMSZaMGJdCD3eU 5AvLNsew==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nFKMk-00FbFv-Pl; Wed, 02 Feb 2022 18:28:26 +0000 Date: Wed, 2 Feb 2022 18:28:26 +0000 From: Matthew Wilcox To: Muchun Song Cc: dan.j.williams@intel.com, jack@suse.cz, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, apopple@nvidia.com, shy828301@gmail.com, rcampbell@nvidia.com, hughd@google.com, xiyuyang19@fudan.edu.cn, kirill.shutemov@linux.intel.com, zwisler@kernel.org, hch@infradead.org, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, duanxiongchun@bytedance.com Subject: Re: [PATCH v2 3/6] mm: page_vma_mapped: support checking if a pfn is mapped into a vma Message-ID: References: <20220202143307.96282-1-songmuchun@bytedance.com> <20220202143307.96282-4-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220202143307.96282-4-songmuchun@bytedance.com> X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 15EA9180005 X-Stat-Signature: yqqrdahc1cz1ckcx5y1cjfi5to6w7fkb Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="Pc3z+/fG"; dmarc=none; spf=none (imf16.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Rspam-User: nil X-HE-Tag: 1643826528-340166 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Feb 02, 2022 at 10:33:04PM +0800, Muchun Song wrote: > page_vma_mapped_walk() is supposed to check if a page is mapped into a vma. > However, not all page frames (e.g. PFN_DEV) have a associated struct page > with it. There is going to be some duplicate codes similar with this function > if someone want to check if a pfn (without a struct page) is mapped into a > vma. So add support for checking if a pfn is mapped into a vma. In the next > patch, the dax will use this new feature. I'm coming to more or less the same solution for fixing the bug in page_mapped_in_vma(). If you call it with a head page, it will look for any page in the THP instead of the precise page. I think we can do a fairly significant simplification though, so I'm going to go off and work on that next ...