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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 CB866C12002 for ; Wed, 21 Jul 2021 11:39:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F7C060FD7 for ; Wed, 21 Jul 2021 11:39:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233183AbhGUK6D (ORCPT ); Wed, 21 Jul 2021 06:58:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238015AbhGUKmn (ORCPT ); Wed, 21 Jul 2021 06:42:43 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A898DC061574; Wed, 21 Jul 2021 04:23:20 -0700 (PDT) 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=tjKLXf0Ng52UH5nHxMTM/eP+9xIaqoGvYekhvlgulkU=; b=ml92iat7e/0Z0zUSXyBKWCFT/T +LyfOBlYqxlteYRIYhfLZunuiaY0K4ewec4QNxKTsAhIvGnLKyEVhhQanm/af+BF2OtFcRhk4GElJ 5a3qkimaAA9z/UuwPVhjWwfSHWIRErSBHjJL2JkvMkmBc4Ceclrfn77wnaYSomg+bKyW7LR23ZWw5 SfrPRbkNbOVXp2zoGMtiZYFHSqjVuP96NiR3So0JPPEWP/nd/By1Hku3hx2ymY4pO1kMLzEYCbI9Q LI5fLcJlj77T+vGjXJtV8j+oeZfRQ1PDsGlSIZCUVZStjZsZeWA0daIESAeCtuBMJlF/PReDVvnGc fQJ7Kptw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6AJh-0097oC-3n; Wed, 21 Jul 2021 11:23:10 +0000 Date: Wed, 21 Jul 2021 12:23:09 +0100 From: Matthew Wilcox To: Mike Rapoport Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v14 011/138] mm/lru: Add folio LRU functions Message-ID: References: <20210715033704.692967-1-willy@infradead.org> <20210715033704.692967-12-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 21, 2021 at 11:39:15AM +0300, Mike Rapoport wrote: > On Wed, Jul 21, 2021 at 05:08:44AM +0100, Matthew Wilcox wrote: > > I wanted to turn those last two sentences into a list, but my > > kernel-doc-fu abandoned me. Feel free to submit a follow-on patch to > > fix that ;-) > > Here it is ;-) Did you try it? Here's what that turns into with htmldoc: Description We would like to get this info without a page flag, but the state needs to survive until the folio is last deleted from the LRU, which could be as far down as __page_cache_release. * 1 if folio is a regular filesystem backed page cache folio or a lazily freed anonymous folio (e.g. via MADV_FREE). * 0 if folio is a normal anonymous folio, a tmpfs folio or otherwise ram or swap backed folio. Return An integer (not a boolean!) used to sort a folio onto the right LRU list and to account folios correctly. Yes, we get a bulleted list, but it's placed in the wrong section! Adding linux-doc for additional insight into this problem. For their reference, here's the input: /** * folio_is_file_lru - Should the folio be on a file LRU or anon LRU? * @folio: The folio to test. * * We would like to get this info without a page flag, but the state * needs to survive until the folio is last deleted from the LRU, which * could be as far down as __page_cache_release. * * Return: An integer (not a boolean!) used to sort a folio onto the * right LRU list and to account folios correctly. * * - 1 if @folio is a regular filesystem backed page cache folio * or a lazily freed anonymous folio (e.g. via MADV_FREE). * - 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise * ram or swap backed folio. */ static inline int folio_is_file_lru(struct folio *folio)