From patchwork Tue Jun 22 11:40:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12336933 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=-16.5 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,URIBL_BLOCKED,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 EA6A9C2B9F4 for ; Tue, 22 Jun 2021 11:47:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A067A613BD for ; Tue, 22 Jun 2021 11:47:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A067A613BD 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 F2EB06B0036; Tue, 22 Jun 2021 07:47:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EDE726B006C; Tue, 22 Jun 2021 07:47:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DA7066B0070; Tue, 22 Jun 2021 07:47:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0091.hostedemail.com [216.40.44.91]) by kanga.kvack.org (Postfix) with ESMTP id A96CF6B0036 for ; Tue, 22 Jun 2021 07:47:11 -0400 (EDT) Received: from smtpin39.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 446978249980 for ; Tue, 22 Jun 2021 11:47:11 +0000 (UTC) X-FDA: 78281183862.39.7145E63 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf17.hostedemail.com (Postfix) with ESMTP id D34814006F00 for ; Tue, 22 Jun 2021 11:47:10 +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=8F6CUdBKfSy3DC7yh+T8CRikfk42ztoDDdMP+r7QcNg=; b=HWNw7D082A/OgTHpUNHmGd98Xn aG5WqS74Yr/NmviEVWLB2cVzPmFMQkfC4kXzEnMmb7q2eahyjwOGosd6DoTvEPD908koZ0oijR03z 53C8M57VAFfUOqnnhx2WJCfaUjvNBepJzVT2JpHGasjS5VmrbXIuo9l8W0VbjPCfFC93LMuvm3epS 96Y+wxgNu9rB+XYl+J9YwvaHe9RDAYohJiGrguzPHUxouf1ke8YNCgQ6vbNrSaVjkVw9QqEba2/U9 2te8F49GJWufgo9HLBnuAEF9ajdI6wSbX8NOfODU4qn3BImrDhLrn6ZxOE9dkT1GK3L66H0SyyDgt xnc2U2Gw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lveqZ-00EDhO-JV; Tue, 22 Jun 2021 11:45:59 +0000 From: "Matthew Wilcox (Oracle)" To: akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Layton , "Kirill A . Shutemov" , Vlastimil Babka , William Kucharski , David Howells Subject: [PATCH v12 06/33] mm: Add folio reference count functions Date: Tue, 22 Jun 2021 12:40:51 +0100 Message-Id: <20210622114118.3388190-7-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210622114118.3388190-1-willy@infradead.org> References: <20210622114118.3388190-1-willy@infradead.org> MIME-Version: 1.0 Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=HWNw7D08; dmarc=none; spf=none (imf17.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Rspamd-Server: rspam02 X-Stat-Signature: jwhca9hhqh6c7nfo56w8grjcsgbnnfjq X-Rspamd-Queue-Id: D34814006F00 X-HE-Tag: 1624362430-161608 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: These functions mirror their page reference counterparts. Also add the kernel-doc to the mm-api and correct the return type of page_ref_add_unless() to bool. No change to generated code. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Jeff Layton Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Reviewed-by: David Howells --- Documentation/core-api/mm-api.rst | 1 + include/linux/page_ref.h | 88 ++++++++++++++++++++++++++++++- 2 files changed, 88 insertions(+), 1 deletion(-) diff --git a/Documentation/core-api/mm-api.rst b/Documentation/core-api/mm-api.rst index 2a94e6164f80..5c459ee2acce 100644 --- a/Documentation/core-api/mm-api.rst +++ b/Documentation/core-api/mm-api.rst @@ -98,4 +98,5 @@ More Memory Management Functions .. kernel-doc:: include/linux/page-flags.h .. kernel-doc:: include/linux/mm.h :internal: +.. kernel-doc:: include/linux/page_ref.h .. kernel-doc:: include/linux/mmzone.h diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h index 3a799de8ad52..717d53c9ddf1 100644 --- a/include/linux/page_ref.h +++ b/include/linux/page_ref.h @@ -67,9 +67,31 @@ static inline int page_ref_count(const struct page *page) return atomic_read(&page->_refcount); } +/** + * folio_ref_count - The reference count on this folio. + * @folio: The folio. + * + * The refcount is usually incremented by calls to folio_get() and + * decremented by calls to folio_put(). Some typical users of the + * folio refcount: + * + * - Each reference from a page table + * - The page cache + * - Filesystem private data + * - The LRU list + * - Pipes + * - Direct IO which references this page in the process address space + * + * Return: The number of references to this folio. + */ +static inline int folio_ref_count(const struct folio *folio) +{ + return page_ref_count(&folio->page); +} + static inline int page_count(const struct page *page) { - return atomic_read(&compound_head(page)->_refcount); + return folio_ref_count(page_folio(page)); } static inline void set_page_count(struct page *page, int v) @@ -79,6 +101,11 @@ static inline void set_page_count(struct page *page, int v) __page_ref_set(page, v); } +static inline void folio_set_count(struct folio *folio, int v) +{ + set_page_count(&folio->page, v); +} + /* * Setup the page count before being freed into the page allocator for * the first time (boot or memory hotplug) @@ -95,6 +122,11 @@ static inline void page_ref_add(struct page *page, int nr) __page_ref_mod(page, nr); } +static inline void folio_ref_add(struct folio *folio, int nr) +{ + page_ref_add(&folio->page, nr); +} + static inline void page_ref_sub(struct page *page, int nr) { atomic_sub(nr, &page->_refcount); @@ -102,6 +134,11 @@ static inline void page_ref_sub(struct page *page, int nr) __page_ref_mod(page, -nr); } +static inline void folio_ref_sub(struct folio *folio, int nr) +{ + page_ref_sub(&folio->page, nr); +} + static inline int page_ref_sub_return(struct page *page, int nr) { int ret = atomic_sub_return(nr, &page->_refcount); @@ -111,6 +148,11 @@ static inline int page_ref_sub_return(struct page *page, int nr) return ret; } +static inline int folio_ref_sub_return(struct folio *folio, int nr) +{ + return page_ref_sub_return(&folio->page, nr); +} + static inline void page_ref_inc(struct page *page) { atomic_inc(&page->_refcount); @@ -118,6 +160,11 @@ static inline void page_ref_inc(struct page *page) __page_ref_mod(page, 1); } +static inline void folio_ref_inc(struct folio *folio) +{ + page_ref_inc(&folio->page); +} + static inline void page_ref_dec(struct page *page) { atomic_dec(&page->_refcount); @@ -125,6 +172,11 @@ static inline void page_ref_dec(struct page *page) __page_ref_mod(page, -1); } +static inline void folio_ref_dec(struct folio *folio) +{ + page_ref_dec(&folio->page); +} + static inline int page_ref_sub_and_test(struct page *page, int nr) { int ret = atomic_sub_and_test(nr, &page->_refcount); @@ -134,6 +186,11 @@ static inline int page_ref_sub_and_test(struct page *page, int nr) return ret; } +static inline int folio_ref_sub_and_test(struct folio *folio, int nr) +{ + return page_ref_sub_and_test(&folio->page, nr); +} + static inline int page_ref_inc_return(struct page *page) { int ret = atomic_inc_return(&page->_refcount); @@ -143,6 +200,11 @@ static inline int page_ref_inc_return(struct page *page) return ret; } +static inline int folio_ref_inc_return(struct folio *folio) +{ + return page_ref_inc_return(&folio->page); +} + static inline int page_ref_dec_and_test(struct page *page) { int ret = atomic_dec_and_test(&page->_refcount); @@ -152,6 +214,11 @@ static inline int page_ref_dec_and_test(struct page *page) return ret; } +static inline int folio_ref_dec_and_test(struct folio *folio) +{ + return page_ref_dec_and_test(&folio->page); +} + static inline int page_ref_dec_return(struct page *page) { int ret = atomic_dec_return(&page->_refcount); @@ -161,6 +228,11 @@ static inline int page_ref_dec_return(struct page *page) return ret; } +static inline int folio_ref_dec_return(struct folio *folio) +{ + return page_ref_dec_return(&folio->page); +} + static inline bool page_ref_add_unless(struct page *page, int nr, int u) { bool ret = atomic_add_unless(&page->_refcount, nr, u); @@ -170,6 +242,11 @@ static inline bool page_ref_add_unless(struct page *page, int nr, int u) return ret; } +static inline bool folio_ref_add_unless(struct folio *folio, int nr, int u) +{ + return page_ref_add_unless(&folio->page, nr, u); +} + static inline int page_ref_freeze(struct page *page, int count) { int ret = likely(atomic_cmpxchg(&page->_refcount, count, 0) == count); @@ -179,6 +256,11 @@ static inline int page_ref_freeze(struct page *page, int count) return ret; } +static inline int folio_ref_freeze(struct folio *folio, int count) +{ + return page_ref_freeze(&folio->page, count); +} + static inline void page_ref_unfreeze(struct page *page, int count) { VM_BUG_ON_PAGE(page_count(page) != 0, page); @@ -189,4 +271,8 @@ static inline void page_ref_unfreeze(struct page *page, int count) __page_ref_unfreeze(page, count); } +static inline void folio_ref_unfreeze(struct folio *folio, int count) +{ + page_ref_unfreeze(&folio->page, count); +} #endif