From patchwork Mon Jul 12 03:05:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12369735 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,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 2B0EBC07E96 for ; Mon, 12 Jul 2021 03:25:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C74B06108B for ; Mon, 12 Jul 2021 03:25:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C74B06108B 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 E76BD6B0092; Sun, 11 Jul 2021 23:25:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E4DBA6B0095; Sun, 11 Jul 2021 23:25:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CEF436B0098; Sun, 11 Jul 2021 23:25:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0038.hostedemail.com [216.40.44.38]) by kanga.kvack.org (Postfix) with ESMTP id ABFB66B0092 for ; Sun, 11 Jul 2021 23:25:30 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D3F40231BE for ; Mon, 12 Jul 2021 03:25:29 +0000 (UTC) X-FDA: 78352495578.12.D54C421 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf29.hostedemail.com (Postfix) with ESMTP id 8D7AE9000247 for ; Mon, 12 Jul 2021 03:25:29 +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=nVC+BVk2C7BJc13hyk4hGwQf60siCtkLq/Ed/hMAyaI=; b=axsdhuykGBz7my0QN9WdWBrj0A mukyHjbu6SoY3vNmu+LvF3DIezUNmUF9A3EB3Zov43uxDi+N4EuXJxvKCMSLhNNs76vhAo3CcPEEr FgkbbGa6Vqj5K8tZpOmNl6l8CapknbH60ANdX5Qs2NKcnseKxmc/0rJVZ63WcDNqF11z38zhwy/+E INI6QSx4junvezwQP4v6akJ8ZeulO2o56ihloeiARpyhRlz5urIWoGLOrnYviQiN89hfb5WpBdWYY SAbIwKgyEDw4VS89/9SHeGG8c/dVmokNORAaysKRBuiI0QCflTmKq1S2xP+tjxrH6+dhqdNZMXBF/ EXmlP+hw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2mYL-00Gnyc-DH; Mon, 12 Jul 2021 03:24:28 +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 v13 032/137] mm: Add folio_mapped() Date: Mon, 12 Jul 2021 04:05:16 +0100 Message-Id: <20210712030701.4000097-33-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210712030701.4000097-1-willy@infradead.org> References: <20210712030701.4000097-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 8D7AE9000247 X-Stat-Signature: apzc8uu9iegzttpcjndrz18rewgwpszk Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=axsdhuyk; dmarc=none; spf=none (imf29.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-HE-Tag: 1626060329-969168 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: 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 --- 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 24311e4c08e9..a856c078e040 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1766,6 +1766,7 @@ 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 c15b4af8ef4d..d0061ddf080f 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 d6176bb63629..0c65b260cded 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_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) {