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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFAD3EB64D7 for ; Mon, 26 Jun 2023 17:15:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 60D508E0001; Mon, 26 Jun 2023 13:15:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5BD558D0001; Mon, 26 Jun 2023 13:15:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4856D8E0001; Mon, 26 Jun 2023 13:15:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 39DE98D0001 for ; Mon, 26 Jun 2023 13:15:00 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 9CB428080E for ; Mon, 26 Jun 2023 17:14:59 +0000 (UTC) X-FDA: 80945549118.09.C2B3625 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf21.hostedemail.com (Postfix) with ESMTP id 9765C1C001F for ; Mon, 26 Jun 2023 17:14:57 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=none; spf=pass (imf21.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1687799697; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MCPPpPFh5Z8cSR0+xeGHeJRTVorBAm/+P3hCtLuZNVU=; b=Od8zKHRS3aBjjZM4v0tCmy27LsCYmuzG5iVoeWpkTubVZ/JGMBOa1/O5OsXKQdIqT1N29i 5kuTCnHFBQa5yZ8Su5ymENS3SVS4InLfBEhDcghTDAmlcAgm1D+5M6lPyMbwhFfIge84JQ MQHmsKzyoIN79ZtUGKM8eaFdB4Brj7w= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1687799697; a=rsa-sha256; cv=none; b=RsmWKCId6ylGvPSxrRodOJUIbZrj1WgwuWLAqVmY4tNetZY5JMetJLxL7hKu4IY4CSGk7r hfXdNNdTTFQIOBSGZc9sn68X757aeHRtWE/le2ZyzwFiT9jmRXR16JGKHFf/xp/yWFMX/+ bekZCril0PNGh8GD1fMnG60hrbMdFjE= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=none; spf=pass (imf21.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 864C1150C; Mon, 26 Jun 2023 10:15:40 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9D3913F663; Mon, 26 Jun 2023 10:14:53 -0700 (PDT) From: Ryan Roberts To: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Yin Fengwei , David Hildenbrand , Yu Zhao , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-s390@vger.kernel.org Subject: [PATCH v1 05/10] mm: Implement folio_remove_rmap_range() Date: Mon, 26 Jun 2023 18:14:25 +0100 Message-Id: <20230626171430.3167004-6-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230626171430.3167004-1-ryan.roberts@arm.com> References: <20230626171430.3167004-1-ryan.roberts@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: 878hbi6whwjkw3b7bcygp5azous5tqkt X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 9765C1C001F X-Rspam-User: X-HE-Tag: 1687799697-656476 X-HE-Meta: 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 YqI965iy 5uxeTCT5XjEKG/l50e5mTKn93BCJhNjMhYXH4w20Cku0rgeXGHlt3++CG4uu5mvCqSHamPatJmVHksMgG0oo14CVMXFl+GKLq44HcmZ4ZzoHPOXSwzzYmr0RiUyICyuildiQSLq620K91I5va1vji6cWrEX37NKYMfRCyOUdPQPM9DkOwY2TscQaNcReVCCn7N0K4q1rRvJAfXDE= 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: Like page_remove_rmap() but batch-removes the rmap for a range of pages belonging to a folio, for effciency savings. All pages are accounted as small pages. Signed-off-by: Ryan Roberts --- include/linux/rmap.h | 2 ++ mm/rmap.c | 62 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 15433a3d0cbf..50f50e4cb0f8 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -204,6 +204,8 @@ void folio_add_file_rmap_range(struct folio *, struct page *, unsigned int nr, struct vm_area_struct *, bool compound); void page_remove_rmap(struct page *, struct vm_area_struct *, bool compound); +void folio_remove_rmap_range(struct folio *folio, struct page *page, + int nr, struct vm_area_struct *vma); void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long address, rmap_t flags); diff --git a/mm/rmap.c b/mm/rmap.c index 4050bcea7ae7..ac1d93d43f2b 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1434,6 +1434,68 @@ void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, folio_add_file_rmap_range(folio, page, nr_pages, vma, compound); } +/* + * folio_remove_rmap_range - take down pte mappings from a range of pages + * belonging to a folio. All pages are accounted as small pages. + * @folio: folio that all pages belong to + * @page: first page in range to remove mapping from + * @nr: number of pages in range to remove mapping from + * @vma: the vm area from which the mapping is removed + * + * The caller needs to hold the pte lock. + */ +void folio_remove_rmap_range(struct folio *folio, struct page *page, + int nr, struct vm_area_struct *vma) +{ + atomic_t *mapped = &folio->_nr_pages_mapped; + int nr_unmapped = 0; + int nr_mapped; + bool last; + enum node_stat_item idx; + + VM_BUG_ON_FOLIO(folio_test_hugetlb(folio), folio); + + if (!folio_test_large(folio)) { + /* Is this the page's last map to be removed? */ + last = atomic_add_negative(-1, &page->_mapcount); + nr_unmapped = last; + } else { + for (; nr != 0; nr--, page++) { + /* Is this the page's last map to be removed? */ + last = atomic_add_negative(-1, &page->_mapcount); + if (last) { + /* Page still mapped if folio mapped entirely */ + nr_mapped = atomic_dec_return_relaxed(mapped); + if (nr_mapped < COMPOUND_MAPPED) + nr_unmapped++; + } + } + } + + if (nr_unmapped) { + idx = folio_test_anon(folio) ? NR_ANON_MAPPED : NR_FILE_MAPPED; + __lruvec_stat_mod_folio(folio, idx, -nr_unmapped); + + /* + * Queue anon THP for deferred split if we have just unmapped at + * least 1 page, while at least 1 page remains mapped. + */ + if (folio_test_large(folio) && folio_test_anon(folio)) + if (nr_mapped) + deferred_split_folio(folio); + } + + /* + * It would be tidy to reset folio_test_anon mapping when fully + * unmapped, but that might overwrite a racing page_add_anon_rmap + * which increments mapcount after us but sets mapping before us: + * so leave the reset to free_pages_prepare, and remember that + * it's only reliable while mapped. + */ + + munlock_vma_folio(folio, vma, false); +} + /** * page_remove_rmap - take down pte mapping from a page * @page: page to remove mapping from -- 2.25.1