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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 9A45EC4338F for ; Wed, 25 Aug 2021 06:40:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 13837610E8 for ; Wed, 25 Aug 2021 06:40:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 13837610E8 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 96EC96B006C; Wed, 25 Aug 2021 02:40:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 91FF78D0001; Wed, 25 Aug 2021 02:40:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 80CFF6B0072; Wed, 25 Aug 2021 02:40:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0121.hostedemail.com [216.40.44.121]) by kanga.kvack.org (Postfix) with ESMTP id 64C866B006C for ; Wed, 25 Aug 2021 02:40:45 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 095E223E41 for ; Wed, 25 Aug 2021 06:40:45 +0000 (UTC) X-FDA: 78512654850.30.42BCADF Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf14.hostedemail.com (Postfix) with ESMTP id B45D760019A0 for ; Wed, 25 Aug 2021 06:40:44 +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=wwqc+zlpZGVWv443QpD/4AYHkmaNpxQkxiVuNbJuNzY=; b=WHUZ/i1haxgYWOz/PEBlGBLX++ ghSazm9VoZ/t+9OplOg6sDgUbKJu5h6aKxmGAiFnJeqWpcYpgS8Yq2yvZGEzzexoZd4NQx2Si4qsZ spEMZATV2k6j74ih9qBI4JpKg1fPh0fYN7EiphdjD7IKDpvP4YhCUYvFn0MYDX059LOxNcwm6REd6 SsFz1xZppsSvJJTHaZeCA3k8YX0TlH9SNSf1M23MoYYBnBPd8wzmQVVjSzSZmrcDnq61POMRZlWfU UiJ1yq24wmlAkg0of1QvBzXo1eTXC6EAgkwww4NLJmLSSt42ScqO4Q/9W+8rj/QWIGy/p6fX0n4fp CdTUsV1Q==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mImZ5-00Bz9a-22; Wed, 25 Aug 2021 06:39:25 +0000 Date: Wed, 25 Aug 2021 07:39:11 +0100 From: Christoph Hellwig To: Linus Torvalds Cc: Johannes Weiner , Matthew Wilcox , Linux-MM , linux-fsdevel , Linux Kernel Mailing List , Andrew Morton Subject: Re: [GIT PULL] Memory folios for v5.15 Message-ID: References: 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 casper.infradead.org. See http://www.infradead.org/rpr.html Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="WHUZ/i1h"; dmarc=none; spf=none (imf14.hostedemail.com: domain of BATV@casper.srs.infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=BATV@casper.srs.infradead.org X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B45D760019A0 X-Stat-Signature: 1onwprasyzxea9icbsgtbmomc9jnfkm9 X-HE-Tag: 1629873644-953407 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 Tue, Aug 24, 2021 at 11:59:52AM -0700, Linus Torvalds wrote: > But it is a lot of churn. And it basically duplicates all our page > functions, just to have those simplified versions. And It's very core > code, and while I appreciate the cleverness of the "folio" name, I do > think it makes the end result perhaps subtler than it needs to be. Maybe I'm biassed by looking at the file system and pagecache side mostly, but if you look at the progress willy has been making a lot of the relevant functionality will exist in either folio or page versions, not both. A lot of the duplication is to support the following: > The one thing I do like about it is how it uses the type system to be > incremental.