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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6AF19C4361B for ; Wed, 16 Dec 2020 13:06:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BF3162339F for ; Wed, 16 Dec 2020 13:06:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF3162339F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D26656B005D; Wed, 16 Dec 2020 08:06:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CD6CC6B0068; Wed, 16 Dec 2020 08:06:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BED946B006C; Wed, 16 Dec 2020 08:06:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0103.hostedemail.com [216.40.44.103]) by kanga.kvack.org (Postfix) with ESMTP id A2E4C6B005D for ; Wed, 16 Dec 2020 08:06:13 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 5DE838249980 for ; Wed, 16 Dec 2020 13:06:13 +0000 (UTC) X-FDA: 77599168626.12.desk86_2f078a42742c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id 3D7E6180033D3 for ; Wed, 16 Dec 2020 13:06:13 +0000 (UTC) X-HE-Tag: desk86_2f078a42742c X-Filterd-Recvd-Size: 2738 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Wed, 16 Dec 2020 13:06:12 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3B785AC7B; Wed, 16 Dec 2020 13:06:11 +0000 (UTC) Date: Wed, 16 Dec 2020 14:06:07 +0100 From: Oscar Salvador To: Muchun Song Cc: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v9 03/11] mm/hugetlb: Free the vmemmap pages associated with each HugeTLB page Message-ID: <20201216130602.GA29394@linux> References: <20201213154534.54826-1-songmuchun@bytedance.com> <20201213154534.54826-4-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201213154534.54826-4-songmuchun@bytedance.com> User-Agent: Mutt/1.10.1 (2018-07-13) 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 Sun, Dec 13, 2020 at 11:45:26PM +0800, Muchun Song wrote: > + > +/* > + * vmemmap_rmap_walk - walk vmemmap page table > + * > + * @rmap_pte: called for each non-empty PTE (lowest-level) entry. > + * @reuse: the page which is reused for the tail vmemmap pages. > + * @vmemmap_pages: the list head of the vmemmap pages that can be freed. > + */ > +struct vmemmap_rmap_walk { > + void (*rmap_pte)(pte_t *pte, unsigned long addr, > + struct vmemmap_rmap_walk *walk); > + struct page *reuse; > + struct list_head *vmemmap_pages; > +}; Why did you chose this approach in this version? Earlier versions of this patchset had a single vmemmap_to_pmd() function which returned the PMD, and now we have serveral vmemmap_{levels}_range and a vmemmap_rmap_walk. A brief explanation about why this change was introduced would have been nice. I guess it is because ealier versions were too oriented for the usecase this patchset presents, while the new versions tries to be more broad about future re-uses of the interface? -- Oscar Salvador SUSE L3