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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E12EEC433EF for ; Sat, 23 Oct 2021 05:02:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CF5BE60FF2 for ; Sat, 23 Oct 2021 05:02:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org CF5BE60FF2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id E2B46940008; Sat, 23 Oct 2021 01:02:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DB6BF940007; Sat, 23 Oct 2021 01:02:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C2CF5940008; Sat, 23 Oct 2021 01:02:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0089.hostedemail.com [216.40.44.89]) by kanga.kvack.org (Postfix) with ESMTP id AC602940007 for ; Sat, 23 Oct 2021 01:02:50 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 6329E3015E for ; Sat, 23 Oct 2021 05:02:50 +0000 (UTC) X-FDA: 78726507300.28.E4B2E74 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf22.hostedemail.com (Postfix) with ESMTP id ACC5D1903 for ; Sat, 23 Oct 2021 05:02:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=hKfR3/ryyitNRCxx14thpt1Pe6SRC47enbuHQnqPb6s=; b=ecpD4Qwjh5T3agQ5qTTl8GtazS w8HThPRzeXp2YcS37McMWS94pO36xXo9FG7zvEhc06IFsxSbb2Qwlo7FtOje/iP67fHEZg64yh3vi Mm5TaOJFNsqbf3MjFPFmmsp6iFcOcCKyd9Mafs/Z3z1nTJ0coG3N/xzJ/dpYyTfapY1HadzEXakKI bVw8DDn5qKYrD8XMGtYjvwvM13VlF49ex+gPSA2+TzT7cOpsK/u/V2jKSqnSQ8YWLdSDNbi/JUhmW blKvlxteuJ2MNVZatZET1jlnTSEGTVZpI5E4A3w1fCxoV5NNR66RLiS3yXsSdCPoIt5JorLe8TTVa KxFz70TA==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1me9Av-00CHxV-Uc; Sat, 23 Oct 2021 05:02:33 +0000 Date: Fri, 22 Oct 2021 22:02:33 -0700 From: Christoph Hellwig To: Matthew Wilcox Cc: David Hildenbrand , Johannes Weiner , Kent Overstreet , "Kirill A. Shutemov" , Linus Torvalds , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , "Darrick J. Wong" , Christoph Hellwig , David Howells , Hugh Dickins Subject: Re: Folios for 5.15 request - Was: re: Folio discussion recap - Message-ID: References: <20211018231627.kqrnalsi74bgpoxu@box.shutemov.name> <326b5796-6ef9-a08f-a671-4da4b04a2b4f@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Stat-Signature: 3eq4ks9c9i1ctrhrjj6gzzzh5xqajnme Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=ecpD4Qwj; spf=none (imf22.hostedemail.com: domain of BATV+7063b6838f15e3f87419+6635+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+7063b6838f15e3f87419+6635+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: ACC5D1903 X-HE-Tag: 1634965369-461491 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 Sat, Oct 23, 2021 at 03:22:35AM +0100, Matthew Wilcox wrote: > You can see folios as a first step to disentangling some of the users > of struct page. It certainly won't be the last step. But I'd really > like to stop having theoretical discussions of memory types and get on > with writing code. Agreed. I think folios are really important to sort out the mess around compound pages ASAP. I'm a lot more lukewarm on the other splits. Yes, struct page is a mess, but I'm not sure creating gazillions of new types solve that mess. Getting rid of a bunch of the crazy optimizations that abuse struct page fields might a better first step - or rather after the first step of folios which fix real bugs in compount handling and do enable sane handling of compound pages in the page cache. > If that means we modify the fs APIs again in twelve > months to replace folios with file_mem, well, I'm OK with that. I suspect we won't even need that so quickly if at all, but I'd rather have a little more churn rather than blocking this important work forever.