From patchwork Thu Jul 15 03:35:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12378513 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 8EA99C07E96 for ; Thu, 15 Jul 2021 04:04:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7303961279 for ; Thu, 15 Jul 2021 04:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234069AbhGOEHL (ORCPT ); Thu, 15 Jul 2021 00:07:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233682AbhGOEHJ (ORCPT ); Thu, 15 Jul 2021 00:07:09 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F14DC06175F; Wed, 14 Jul 2021 21:04:16 -0700 (PDT) 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=DsXeC5XdMN2GjsT/d/z6VoHbwVOhzpi66MJ1omvf8Uk=; b=hg44rZIh4hZrPqzvGWOX9VqItF yP93TzpK+MSy9WNugWotTGxWzVePmwe1VyilhMuy1jHp2LRgcDdBem6CMxAE5O3yU68zKVQCihnV0 rLvHebpZHDO57hCVekJxUtSDULLSMUuowXFeSAabNfasXA3QLXBnTMBD6Ruqq3qQ5N3Qd5+5AKnfy /e36ief9/oRuFq4o9TpaR9mS7fyWw6d+3KeiG+p/IMqKlOlIJ/KFXSsZiUrL5xIEacoEB1fhxFkS5 3WpzP9D/J1VHZXMupG6AQCr0Om2eQE1/kVwlz+/CcUPh6oZTTpaEUh8BgLw5GukZTYrq515wEv0hc N52dRufQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3saN-002voT-HI; Thu, 15 Jul 2021 04:03:18 +0000 From: "Matthew Wilcox (Oracle)" To: linux-kernel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Vlastimil Babka , William Kucharski , Christoph Hellwig , David Howells , "Kirill A . Shutemov" Subject: [PATCH v14 032/138] mm: Add folio_mapped() Date: Thu, 15 Jul 2021 04:35:18 +0100 Message-Id: <20210715033704.692967-33-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210715033704.692967-1-willy@infradead.org> References: <20210715033704.692967-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This function is the equivalent of page_mapped(). It is slightly shorter as we do not need to handle the PageTail() case. Reimplement page_mapped() as a wrapper around folio_mapped(). folio_mapped() is 13 bytes smaller than page_mapped(), but the page_mapped() wrapper is 30 bytes, for a net increase of 17 bytes of text. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Reviewed-by: Christoph Hellwig Reviewed-by: David Howells Acked-by: Kirill A. Shutemov Acked-by: Mike Rapoport --- include/linux/mm.h | 1 + include/linux/mm_types.h | 6 ++++++ mm/folio-compat.c | 6 ++++++ mm/util.c | 29 ++++++++++++++++------------- 4 files changed, 29 insertions(+), 13 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 9d28f5b2e983..8b79d9dfa6cb 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1767,6 +1767,7 @@ static inline pgoff_t page_index(struct page *page) } bool page_mapped(struct page *page); +bool folio_mapped(struct folio *folio); /* * Return true only if the page has been allocated with diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index c4dd41bb1019..f763aa273d82 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -291,6 +291,12 @@ FOLIO_MATCH(memcg_data, memcg_data); #endif #undef FOLIO_MATCH +static inline atomic_t *folio_mapcount_ptr(struct folio *folio) +{ + struct page *tail = &folio->page + 1; + return &tail->compound_mapcount; +} + static inline atomic_t *compound_mapcount_ptr(struct page *page) { return &page[1].compound_mapcount; diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 3c83f03b80d7..7044fcc8a8aa 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -35,3 +35,9 @@ void wait_for_stable_page(struct page *page) return folio_wait_stable(page_folio(page)); } EXPORT_SYMBOL_GPL(wait_for_stable_page); + +bool page_mapped(struct page *page) +{ + return folio_mapped(page_folio(page)); +} +EXPORT_SYMBOL(page_mapped); diff --git a/mm/util.c b/mm/util.c index 1cde6218d6d1..e8c12350b3eb 100644 --- a/mm/util.c +++ b/mm/util.c @@ -652,28 +652,31 @@ void *page_rmapping(struct page *page) return __page_rmapping(page); } -/* - * Return true if this page is mapped into pagetables. - * For compound page it returns true if any subpage of compound page is mapped. +/** + * folio_mapped - Is this folio mapped into userspace? + * @folio: The folio. + * + * Return: True if any page in this folio is referenced by user page tables. */ -bool page_mapped(struct page *page) +bool folio_mapped(struct folio *folio) { - int i; + int i, nr; - if (likely(!PageCompound(page))) - return atomic_read(&page->_mapcount) >= 0; - page = compound_head(page); - if (atomic_read(compound_mapcount_ptr(page)) >= 0) + if (folio_single(folio)) + return atomic_read(&folio->_mapcount) >= 0; + if (atomic_read(folio_mapcount_ptr(folio)) >= 0) return true; - if (PageHuge(page)) + if (folio_test_hugetlb(folio)) return false; - for (i = 0; i < compound_nr(page); i++) { - if (atomic_read(&page[i]._mapcount) >= 0) + + nr = folio_nr_pages(folio); + for (i = 0; i < nr; i++) { + if (atomic_read(&folio_page(folio, i)->_mapcount) >= 0) return true; } return false; } -EXPORT_SYMBOL(page_mapped); +EXPORT_SYMBOL(folio_mapped); struct anon_vma *page_anon_vma(struct page *page) {