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 85259C5DF62 for ; Wed, 26 Jan 2022 20:38:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1112A6B0072; Wed, 26 Jan 2022 15:38:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0C09E6B0075; Wed, 26 Jan 2022 15:38:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EF0CB6B007B; Wed, 26 Jan 2022 15:38:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay029.a.hostedemail.com [64.99.140.29]) by kanga.kvack.org (Postfix) with ESMTP id DF6FE6B0072 for ; Wed, 26 Jan 2022 15:38:27 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 95B2420B7A for ; Wed, 26 Jan 2022 20:38:27 +0000 (UTC) X-FDA: 79073601054.02.6CA3CA4 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf22.hostedemail.com (Postfix) with ESMTP id CBA23C0040 for ; Wed, 26 Jan 2022 20:38:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:Message-ID: Subject:To:From:Date:Sender:Reply-To:Cc:Content-Transfer-Encoding:Content-ID: Content-Description:In-Reply-To:References; bh=ITwUUduvHGoqzChBubtdaEjI4Y8oSKQFVPed7lBjssw=; b=cUgP1qzoHQMfa1Kzd2pfNtV9S+ 63IbUP6eeSx7vcifOvwDGG1i4dGjk1xjxjd2r33QA4+qvY88bs7lTUDfnkzHhpCDvMV2yTRsGCL6s YkIT3mAf4KgTht6Y83arEx3mwQJYigXj0DeetBzuEV75uPte2396K4Lj81BQDb+Xw42wIaqMwU0Us jklIyCZmtcsLh+vY/6Cke1sX8jOZXFj6bgibGmtyNqoorbhSnRbZWuooh4W+NvX2jEldRc3d7r6jA yVPSkkEFaljN/2JZL7e3X+/DRuJ6KCK4AF26l2/JzEFQfGQC0oTFHf0EIP859ADX/Dkl7ewyTwAhk CKB5ryLw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCp3c-004RNS-WD; Wed, 26 Jan 2022 20:38:21 +0000 Date: Wed, 26 Jan 2022 20:38:20 +0000 From: Matthew Wilcox To: lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [LSF/MM/BPF TOPIC] Folios Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: CBA23C0040 X-Stat-Signature: bpxjs86htbwjbjem5uumtta3dcwjskap Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=cUgP1qzo; dmarc=none; spf=none (imf22.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: 1643229506-123892 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000136, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: You might think that with a fortnightly meeting, presentations on the subject of folios at several conferences and hundreds of patches merged, I'd be short of things to discuss at LSFMM. Hah. >From a filesystem point of view, - Converting APIs that filesystems implement to use folios (aops, primarily) to be folio based instead of page based - What it takes to support large (ie multi-page) folios in your filesystem - Removing old page-based APIs used by filesystems (eg everything in mm/folio-compat.c) - Converting your filesystem to use iomap. For the MM crowd: - Continued conversion of the MM from pages to folios - GUP is done - page_vma_mapped is done, not yet posted for review - rmap in progress - mlock in progress - vmscan in progress (this list will have changed by May) - Splitting out other page types from struct page - Dynamically allocating struct folio & shrinking struct page I'm going to throw a discussion of mapcount into this as well; getting mapcount right on a multi-page folio is expensive. I intend to send a full proposal for making mapcount less accurate by default soon; just haven't found time to do it yet.