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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 D7C05C433E0 for ; Fri, 5 Mar 2021 04:21:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7357965009 for ; Fri, 5 Mar 2021 04:21:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7357965009 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 108706B0007; Thu, 4 Mar 2021 23:21:29 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0E1216B0008; Thu, 4 Mar 2021 23:21:29 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EC3B26B000A; Thu, 4 Mar 2021 23:21:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0097.hostedemail.com [216.40.44.97]) by kanga.kvack.org (Postfix) with ESMTP id CD55E6B0007 for ; Thu, 4 Mar 2021 23:21:28 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 8BED1181AEF10 for ; Fri, 5 Mar 2021 04:21:28 +0000 (UTC) X-FDA: 77884521456.04.2AA98F5 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf17.hostedemail.com (Postfix) with ESMTP id D889A40001DE for ; Fri, 5 Mar 2021 04:21:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=VTFfmSh3PtwZWFi9FZ9t/kJrbRPQg2Phw+OnoZy+bTo=; b=FeDX+TJ7yiCS7D3DPp2FWORI0Z 67MDf1+YHsLWiW14UZeVUfTITA8le6UqpwTPq2/duAAfwTNk97c+S4beIQfjJXCr9E2QE0Qoymwu0 ITKHEC9t7YRRWalsjC6niGbQXqk5rhE4Lk4E7bonvtdOvQNhfoYd1kKsmWogUkZyTdLt3SwBtzdSr tSbY8b2s9vrciwG8zhE1zmJVe/SxGvPbKDoT6yYCLd+a5P64/halNz5uJ0xirA7oMPov8WUBASs40 KQh7agI9n0CTMb+cCkKOstq9SYUxzBaAinloxaLESoyyQXHDyFykyib+DCZdSwfEvHflIzYxv4hCy /q7H9jEQ==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lI1wg-00A3Zj-Tw; Fri, 05 Mar 2021 04:20:22 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v4 08/25] mm: Handle per-folio private data Date: Fri, 5 Mar 2021 04:18:44 +0000 Message-Id: <20210305041901.2396498-9-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210305041901.2396498-1-willy@infradead.org> References: <20210305041901.2396498-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: D889A40001DE X-Stat-Signature: ibkzbzecwhds45jzzianed7m9t346hfn Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf17; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614918087-890358 Content-Transfer-Encoding: quoted-printable 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: Add folio_private() and set_folio_private() which mirror page_private() and set_page_private() -- ie folio private data is the same as page private data. Turn attach_page_private() into attach_folio_private() and reimplement attach_page_private() as a wrapper. No filesystem which uses page privat= e data currently supports compound pages, so we're free to define the rules= . attach_page_private() may only be called on a head page; if you want to add private data to a tail page, you can call set_page_private() directly (and shouldn't increment the page refcount! That should be done when adding private data to the head page / folio). This saves 886 bytes of text with the distro-derived config that I'm testing due to removing the calls to compound_head() in get_page() & put_page(). Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/mm_types.h | 16 ++++++++++++++ include/linux/pagemap.h | 48 ++++++++++++++++++++++++---------------- 2 files changed, 45 insertions(+), 19 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index a311cb48526f..b650423fcba6 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -258,6 +258,12 @@ static inline atomic_t *compound_pincount_ptr(struct= page *page) #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) =20 +/* + * page_private can be used on tail pages. However, PagePrivate is only + * checked by the VM on the head page. So page_private on the tail page= s + * should be used for data that's ancillary to the head page (eg attachi= ng + * buffer heads to tail pages after attaching buffer heads to the head p= age) + */ #define page_private(page) ((page)->private) =20 static inline void set_page_private(struct page *page, unsigned long pri= vate) @@ -265,6 +271,16 @@ static inline void set_page_private(struct page *pag= e, unsigned long private) page->private =3D private; } =20 +static inline unsigned long folio_private(struct folio *folio) +{ + return folio->page.private; +} + +static inline void set_folio_private(struct folio *folio, unsigned long = v) +{ + folio->page.private =3D v; +} + struct page_frag_cache { void * va; #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 20225b067583..f07c03da83f6 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -245,42 +245,52 @@ static inline int page_cache_add_speculative(struct= page *page, int count) } =20 /** - * attach_page_private - Attach private data to a page. - * @page: Page to attach data to. - * @data: Data to attach to page. + * attach_folio_private - Attach private data to a folio. + * @folio: Folio to attach data to. + * @data: Data to attach to folio. * - * Attaching private data to a page increments the page's reference coun= t. - * The data must be detached before the page will be freed. + * Attaching private data to a folio increments the page's reference cou= nt. + * The data must be detached before the folio will be freed. */ -static inline void attach_page_private(struct page *page, void *data) +static inline void attach_folio_private(struct folio *folio, void *data) { - get_page(page); - set_page_private(page, (unsigned long)data); - SetPagePrivate(page); + get_folio(folio); + set_folio_private(folio, (unsigned long)data); + SetFolioPrivate(folio); } =20 /** - * detach_page_private - Detach private data from a page. - * @page: Page to detach data from. + * detach_folio_private - Detach private data from a folio. + * @folio: Folio to detach data from. * - * Removes the data that was previously attached to the page and decreme= nts + * Removes the data that was previously attached to the folio and decrem= ents * the refcount on the page. * - * Return: Data that was attached to the page. + * Return: Data that was attached to the folio. */ -static inline void *detach_page_private(struct page *page) +static inline void *detach_folio_private(struct folio *folio) { - void *data =3D (void *)page_private(page); + void *data =3D (void *)folio_private(folio); =20 - if (!PagePrivate(page)) + if (!FolioPrivate(folio)) return NULL; - ClearPagePrivate(page); - set_page_private(page, 0); - put_page(page); + ClearFolioPrivate(folio); + set_folio_private(folio, 0); + put_folio(folio); =20 return data; } =20 +static inline void attach_page_private(struct page *page, void *data) +{ + attach_folio_private((struct folio *)page, data); +} + +static inline void *detach_page_private(struct page *page) +{ + return detach_folio_private((struct folio *)page); +} + #ifdef CONFIG_NUMA extern struct page *__page_cache_alloc(gfp_t gfp); #else --=20 2.30.0