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 15DB1C48286 for ; Sun, 4 Feb 2024 10:39:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6DF2A6B0074; Sun, 4 Feb 2024 05:39:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 68F696B0075; Sun, 4 Feb 2024 05:39:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5A4F66B0078; Sun, 4 Feb 2024 05:39:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 4BDEB6B0074 for ; Sun, 4 Feb 2024 05:39:50 -0500 (EST) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id EB2921A069B for ; Sun, 4 Feb 2024 10:39:49 +0000 (UTC) X-FDA: 81753775698.12.CF2D346 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf08.hostedemail.com (Postfix) with ESMTP id EA359160002 for ; Sun, 4 Feb 2024 10:39:47 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=R0+vADoN; spf=pass (imf08.hostedemail.com: domain of rppt@kernel.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1707043188; a=rsa-sha256; cv=none; b=fpB8kZLNfWwHywM3PiE2F7Y1y0PgI6r8lONpJk+RolaBU9FNEYtBWSPSgKPGXPlql2wUW9 nMWyoBpXzjhjqCgWsrqRRjmN3RJb8G++zUYqZHWbK00tbEDQbWW7JBeR1NvliEVnw9Ttir WNNJBNIpjs+Qxjm2TR5zVbt4fsicGu0= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=R0+vADoN; spf=pass (imf08.hostedemail.com: domain of rppt@kernel.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1707043188; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/HNW6CZgXXHsA80ADjLnhidXNGn3Kis5WgWYh/g8/iE=; b=fo0EC1+PumMXMpur9cO9fZwfsw1BUPrmTiKFUFGQ5hzD8A4cms3c5bQNZCUDd0DzeNZBd6 i5V9f7St/28VRGD1U+NOVbz4w5AROF+LLj1vSy6MIBnjKxF3MWOwEhveeX2do6rqme5NFM QplLJl68of0740gdk+ASbYv/SHJQunA= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 47F29CE0171; Sun, 4 Feb 2024 10:39:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 182E9C433C7; Sun, 4 Feb 2024 10:39:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707043183; bh=iyoxJyYS1ovHgfgZClsPvcow6R3PPCC0we47Uz+xt0M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R0+vADoNlIEK5wCnNQUPTWplg8vqRoOQ4lErZPgwdFQHb6X028MomFpHeBXXxYqQW ewbTxmEY40Ffr8SbpyQqvQCmf5eAb9Gbi2qIc0eqUyRdmKwkrS8K+EE12tFZpAgSDb duK0oUTehJb7GDqCv+SeDW+buwKdH/1sxkFn49uTRHpkxRCJbWYINuL3Z3CeY/46GE eANkCxw7ZyWaPDphTfuuQ6nme1uck+O3CAxa1n9lCCHqS2YFK309CEOXohK+ggkkZE dtoZtoe8t+kA8hwH9jeFbG/l3ydjG65LLwk17sCIr5C9D1NAfZf7JwE8mtaSSU2pkO qBHfhlIXCe33w== Date: Sun, 4 Feb 2024 11:39:33 +0100 From: Mike Rapoport To: Matthew Wilcox Cc: lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvme@lists.infradead.org, bpf@vger.kernel.org Subject: Re: [LSF/MM/BPF TOPIC] Reclaiming & documenting page flags Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: EA359160002 X-Stat-Signature: to4118wwpfg9ax1mhau9e5noguzqzbyk X-Rspam-User: X-HE-Tag: 1707043187-154630 X-HE-Meta: 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 /zdhX1LI WP/o14rwB8FjLxuoUdeti5yw9xY9sh78h3jnprc5XqbX474CjVg1foFxjPk8aPwjU2M+ItAlDmm39aGVPmGI8AMJqPAaluy2J05Q3fgKXaNdGaS0lRD9mOBmOGsjkXtOZay2lKq0vb2v0OQLuzvx6ziPQPqY88sQRK6giMOYngtj5P6XKNVNKmO7kpOZt3EJ1m5ZW 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: List-Subscribe: List-Unsubscribe: On Mon, Jan 29, 2024 at 04:32:03AM +0000, Matthew Wilcox wrote: > Our documentation of the current page flags is ... not great. I think > I can improve it for the page cache side of things; I understand the > meanings of locked, writeback, uptodate, dirty, head, waiters, slab, > mlocked, mappedtodisk, error, hwpoison, readahead, anon_exclusive, > has_hwpoisoned, hugetlb and large_remappable. > > Where I'm a lot more shaky is the meaning of the more "real MM" flags, > like active, referenced, lru, workingset, reserved, reclaim, swapbacked, > unevictable, young, idle, swapcache, isolated, and reported. > > Perhaps we could have an MM session where we try to explain slowly and > carefully to each other what all these flags actually mean, talk about > what combinations of them make sense, how we might eliminate some of > them to make more space in the flags word, and what all this looks like > in a memdesc world. > > And maybe we can get some documentation written about it! Not trying > to nerd snipe Jon into attending this session, but if he did ... I suspect Jon will be there anyway, but not sure he'd be willing to do the writing :) I was going to propose the "mm docs" session again, but this one seems more useful than talking yet again about how hard it is to get MM documentation done. And I can take on myself putting the explanations from this session into writing. > [thanks to Amir for reminding me that I meant to propose this topic] > -- Sincerely yours, Mike.