From patchwork Wed Mar 31 18:47:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12175969 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=-13.8 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,UNWANTED_LANGUAGE_BODY, 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 2F0CDC433B4 for ; Wed, 31 Mar 2021 18:49:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C681361007 for ; Wed, 31 Mar 2021 18:49:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C681361007 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 694016B0092; Wed, 31 Mar 2021 14:49:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5F5FE6B0093; Wed, 31 Mar 2021 14:49:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 421916B0095; Wed, 31 Mar 2021 14:49:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0220.hostedemail.com [216.40.44.220]) by kanga.kvack.org (Postfix) with ESMTP id 24B846B0092 for ; Wed, 31 Mar 2021 14:49:13 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D168B181AF5C2 for ; Wed, 31 Mar 2021 18:49:12 +0000 (UTC) X-FDA: 77981056944.20.F25F944 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf01.hostedemail.com (Postfix) with ESMTP id 053D9500152E for ; Wed, 31 Mar 2021 18:49:11 +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=dYXcqubbn/kuXkrXP1knS3VoxabPRjt+5mOpGQ3gMZ8=; b=ssTCJxihHcxjN5MHDDuJSmERTv KFPp2ZjcehCo5r/RMRnY1AUYHH+r7VZW/2nmU51jGC1ZWVP3WgREu99jUiOfKlZ1C77WhTJ9EWZKJ sTkmlOTGkulY46oWjZCyBI2YsgjLmp4J7fTwz9w6RXAFdiMhPxJmgfN9tqUT8zwXEqGJTULsjsqJc LuVuF6wPIEMB/2rDCmtj5hcjQCMyf3+wbXTFP8IBFAWyRm1b5y71Z46RJ6SmxzgHLrcAUq01f4fV9 kwrYUQjdH1QUrrWQHoDhPc+G+gPWg7dzb6sOqFYSo7w9XKFo48571z2cQ/Mrea4Pwyg3KDYTrBH19 lxPpYYNA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lRftP-004zB9-36; Wed, 31 Mar 2021 18:48:51 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com, linux-afs@lists.infradead.org Subject: [PATCH v6 05/27] mm: Add folio reference count functions Date: Wed, 31 Mar 2021 19:47:06 +0100 Message-Id: <20210331184728.1188084-6-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210331184728.1188084-1-willy@infradead.org> References: <20210331184728.1188084-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 053D9500152E X-Stat-Signature: 4qio38yy85z63a6hkssf4384qyonabdc Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617216551-480537 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. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig --- 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 34f46df91a8b..1ead2570b217 100644 --- a/Documentation/core-api/mm-api.rst +++ b/Documentation/core-api/mm-api.rst @@ -97,3 +97,4 @@ More Memory Management Functions :internal: .. kernel-doc:: include/linux/mm.h :internal: +.. kernel-doc:: include/linux/page_ref.h diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h index f3318f34fc54..f27005e760fd 100644 --- a/include/linux/page_ref.h +++ b/include/linux/page_ref.h @@ -69,7 +69,29 @@ static inline int page_ref_count(struct page *page) static inline int page_count(struct page *page) { - return atomic_read(&compound_head(page)->_refcount); + return page_ref_count(compound_head(page)); +} + +/** + * folio_ref_count - The reference count on this folio. + * @folio: The folio. + * + * The refcount is usually incremented by calls to get_folio() and + * decremented by calls to put_folio(). 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(struct folio *folio) +{ + return page_ref_count(&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 set_folio_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 int page_ref_add_unless(struct page *page, int nr, int u) { int ret = atomic_add_unless(&page->_refcount, nr, u); @@ -170,6 +242,11 @@ static inline int page_ref_add_unless(struct page *page, int nr, int u) return ret; } +static inline int 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