From patchwork Tue Feb 18 23:50:11 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zi Yan X-Patchwork-Id: 13981099 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 1C664C021AD for ; Tue, 18 Feb 2025 23:52:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A56E22801B8; Tue, 18 Feb 2025 18:52:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A2FB62801B5; Tue, 18 Feb 2025 18:52:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 880012801B8; Tue, 18 Feb 2025 18:52:22 -0500 (EST) 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 64C4A2801B5 for ; Tue, 18 Feb 2025 18:52:22 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 1BA2F1C77F0 for ; Tue, 18 Feb 2025 23:52:22 +0000 (UTC) X-FDA: 83134716924.07.15FB81E Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2075.outbound.protection.outlook.com [40.107.243.75]) by imf18.hostedemail.com (Postfix) with ESMTP id 4B0581C000B for ; Tue, 18 Feb 2025 23:52:19 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=Ha0PQVyf; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf18.hostedemail.com: domain of ziy@nvidia.com designates 40.107.243.75 as permitted sender) smtp.mailfrom=ziy@nvidia.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1739922739; a=rsa-sha256; cv=pass; b=0boSV6rl1prUOnro2krFAmIzv9TD5kgJOK6yluB25/L2Q8hplRIw9mLrjvPlYRfjVQ0s9e 7zj/IvmVWzG2X/OYHDAtnIn03IcFk5YDskL9hQxvlqcYL0aGE6BuRMjtsVPO6yOtLHOoTN l7m1XW2/lXU80ja3QL3pILK16U2Mmvk= ARC-Authentication-Results: i=2; imf18.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=Ha0PQVyf; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf18.hostedemail.com: domain of ziy@nvidia.com designates 40.107.243.75 as permitted sender) smtp.mailfrom=ziy@nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739922739; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=9PJ7zBIViLKphcXY2b8VdDiqcqFp+9EBhh42TsYKGoA=; b=CuuB+HKsGsOzgLgZRnExgxS6cj2SvLb4e90Zwlf6rbdulRTyj4vm6KEtPiEuGzXrH18Ri4 PNGc2+ws6jtc3HLtnvRpwtc1QKlIfSTzwaaIfSjPdVW+KgRrZy6Q8moyh1NlOGmL+udQA8 2G5bI0JZNjg3FpbzLRj0fC033FwIs5g= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=DgoxzcAhdHtOzXrGDSO0wG7zcc+jtytcdx8ACvfBAG3REmczfwnq1IxHRt6sb238Tg9l/1xoHfIXW2BsxEW+psDZHZQpaV0735XHiGAdA96IVgd548vW5/8RGc1imhXXTchraGpHXaePSrtE7WTCJnULi1lzk5b+Vh5w/ZCqKzH6BjSKD9tMpRzB24+nPFJ7a5YhHV/XECpiIMRRtpyP2RuIQbR2ptVJ9E2o13Fib6sgvq6K4s1vqHV9K1XZ8DQhDJaguimWx8loc8CeP6VQuo0dACW9P65clE8tO1QooqTlWNyYZQSO1nsZphVSbWYetK+ZS0I799DObnOZG9SFvg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=9PJ7zBIViLKphcXY2b8VdDiqcqFp+9EBhh42TsYKGoA=; b=C2Oihr+M2LqagNjXqrgjOiq+4V3jYYtF2bbtaK+Pw9fJ5LMkP9SBs4qC+EbxH+v/Uw+lpKGfsMLXVcVgeqUwZ4ppcrhgRZqcxxltRU1R00Z7e7NcSER78WPi9pgaHSZtfb9yXo+gFyXcDbkpBGftjenFORycqbCCXg8+7FRpUA//BE+go6qbJKSgJhY1X7aiikPQ5vK0H6L57Z1cD4xwmCEJcwtYH+gYfqaofYILy3tYJwzJNWOsdkgWBYVcg+2UMmt9EhJmUF92mWsq8LIW7nRVx9liZYYGW2R2SyxIjnIjyWpW4fv4y7/ojwFCTlRZmYduVN0DmJMEQUit+vsrvg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=9PJ7zBIViLKphcXY2b8VdDiqcqFp+9EBhh42TsYKGoA=; b=Ha0PQVyfv69SJcF0U4RIvgdLtJOpcCEpIFtMmTwTNcpTPcrnV1PEzCpjiiwumvxSpX1P3ptYGXm5D0FXv3TNoz6zHO3w1VxWrw3cCWhUg3Ac2UrDFOo+B9pMAo6UA5Ty0W4R/HftVwEAhNuhMRqhOiilqh/9YXQjALIqU0e8gra1qragmbLpWmAbu0XoI5xc4jRTD5jOCWkFLHinzQfcDZN8JA9CHWvzbihpbujnOyu5cOdJi858nxUdjm2V73lRN0+kIXANDpT6gHHypPg0YDvluKacHptDCxJodtCIbLgVZS0yynJ5K7BmG7m7J5RgoDfcB6fW7NWhCWiNK84DeA== Received: from DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) by CH2PR12MB4326.namprd12.prod.outlook.com (2603:10b6:610:af::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8466.14; Tue, 18 Feb 2025 23:50:27 +0000 Received: from DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a]) by DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a%5]) with mapi id 15.20.8445.017; Tue, 18 Feb 2025 23:50:26 +0000 From: Zi Yan To: linux-mm@kvack.org, Andrew Morton , "Kirill A . Shutemov" , "Matthew Wilcox (Oracle)" Cc: Ryan Roberts , Hugh Dickins , David Hildenbrand , Yang Shi , Miaohe Lin , Kefeng Wang , Yu Zhao , John Hubbard , Baolin Wang , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Zi Yan Subject: [PATCH v8 7/8] mm/truncate: use buddy allocator like folio split for truncate operation Date: Tue, 18 Feb 2025 18:50:11 -0500 Message-ID: <20250218235012.1542225-8-ziy@nvidia.com> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250218235012.1542225-1-ziy@nvidia.com> References: <20250218235012.1542225-1-ziy@nvidia.com> X-ClientProxiedBy: MN2PR22CA0023.namprd22.prod.outlook.com (2603:10b6:208:238::28) To DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR12MB9473:EE_|CH2PR12MB4326:EE_ X-MS-Office365-Filtering-Correlation-Id: 465ef961-511d-49e5-15ee-08dd507704a8 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR12MB9473.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: nZ/X/KKz9HMuuIXuJ+n+Qj1RAvmO55xRM8kh9CEn7SgySC4KzvIkxtdJDS4j5QDy+Rcw+ubhItx9kMzpQs7Qoya7quMdkstv+MKt5MHYd8HUbkBW31nzWjYD6rwm/Ej1h+mYcBrrOCFz5escwZ2CLn0jrB3KmEdMrzEVzRSFYL+kHsyhfQ0yQXdITMZ04AyoHi9MuT09RnDJEO9Qu6oD/nLpVlv33yZ+nTXyWrUE0d29/Nth0oGBxnHJ1u10xQrnud4Up0vwD8OiAKp5M9n88mTtC4lw0KNqXgPyjxUl5LVwFU/lhVx/p4MAedgHFsqDS3yqHY1Q034+jDjm/5s/6mxc8I6za+beGbbTN5YYlTOK9XvWSjFIoll3XsbxuJW7Z321alhaEW3ufDPySQNo3ZKd/9Ib9VHiYbY+b8UnX3b+pZZvfJ6jv3vTGSEETbNyqLFT80N9yXdXZibQEgjzD7U0Bem9mmjYkqYLovtYjk/0vkdb8Oa9ZAH0p2uTrhvL0xus6k9qYdofycbXGs4+1gQ7xF2UScUl579qZ8vL5xUU3EdEYAz+uyKnRpbWzE4tsyckalhM4lnMyQAx78yK0QB2fWvqA85+bdpA66W19onSUExyGbv1LJXAUygbJG2S4WFKOWa7Dvixn/Z9/Kj+1pLJopzTtw0uTocu87bxN49ejI5N6H0sE54o87OTcDP/idIV54lTdkHqu00yn9FlHNWG8bsylFFrQzyaEaJDl6oixNyGUOuiNfz4XSNpZxJKuWKHX+2QY0bBu4y1DPtZtmBo6w57oeUGn/56h3vy6U/FH2Ii0jCa8NNxPpSxyKUPWmg+TrjcqJt3OkqpAB+e0gHOtWwfp/hsAeKVLPFSxDPUzhIkS5QI2iHOExqQEMeN39SfeSNrByn4WLxWB4R7Q4x3iAox/4Xn50BCp9kdhlXAGj60QOFNkDutt2+HUyY1DGmRfaNBLfNzKsIU7tfnx0Yed3Q2n6DZbfmkKntOQKmVQ2cRoB+hsixfzsYxAiR40oAl6ZmHDPjVq/Z1muYVd2vs4t0Vk3XUe8ne1tCfKSHEH+WhdA7c7FWlRiY8lzo0RTawYHCtXDjPkvvkZwn0+5ZN41R8ZqThKpnjmSHPQl0V3bHP5gguo0/kdLHEmqHZg5mdEmZbQayAe1D0ZrMvwTHAUFwCUneus4SXVlRmDkAW11F4S/Yi9TCIipZtQ6hTGXZOg4YowlwA/xhT3MjEvscy8wgVCHyerOU7aMwGHyzgCZLskzxd4KipYevDJklEnnnaa9NVhgsm6bJ64ZbYZhpzSCW6F6lYcDYOw98885Oa6HnhXk7n6cRWW9zqeVy/ShmXlysqkHvXkQkzJOwxq+phmNGE/a/Da+b1Gdc7OkeUTP3KkE8S7Kpc6aNmsjWN2BzS9IgKgWaERxJ6zWXFQvDbAfjuWv07Pg/+vLrr4G3D0cjCd7fs7R5l4MohPwjgXjF+I/at6AVAneVGx0TTVh8vTfHHI3Nyecvc062VhB+GeM2vY/gdi5UfLC/ukO3LumWI5kGMRlsKXADgkfM7OoWdwyIXH8KiOqqt+BsYMQldqxzGpenYZjGgiAOTgTOh X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 465ef961-511d-49e5-15ee-08dd507704a8 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Feb 2025 23:50:26.7105 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: suRP11NNToaNr1A0gWcA0uRZy5sC4hGgMV4qozEZ74qnglBe5VqjMfHH+Xg8vqTC X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR12MB4326 X-Rspam-User: X-Rspamd-Queue-Id: 4B0581C000B X-Rspamd-Server: rspam12 X-Stat-Signature: ot6od58jwps9qnxji6d3knugqrogwioa X-HE-Tag: 1739922739-724827 X-HE-Meta: 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 7Q8LGiMC 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 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: List-Subscribe: List-Unsubscribe: Instead of splitting the large folio uniformly during truncation, try to use buddy allocator like split at the start of truncation range to minimize the number of resulting folios if it is supported. try_folio_split() is introduced to use folio_split() if supported and fall back to uniform split otherwise. For example, to truncate a order-4 folio [0, 1, 2, 3, 4, 5, ..., 15] between [3, 10] (inclusive), folio_split() splits the folio to [0,1], [2], [3], [4..7], [8..15] and [3], [4..7] can be dropped and [8..15] is kept with zeros in [8..10], then another folio_split() is done at 10, so [8..10] can be dropped. One possible optimization is to make folio_split() to split a folio based on a given range, like [3..10] above. But that complicates folio_split(), so it will be investigated when necessary. Signed-off-by: Zi Yan Cc: Baolin Wang Cc: David Hildenbrand Cc: Hugh Dickins Cc: John Hubbard Cc: Kefeng Wang Cc: Kirill A. Shuemov Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Ryan Roberts Cc: Yang Shi Cc: Yu Zhao --- include/linux/huge_mm.h | 36 ++++++++++++++++++++++++++++++++++++ mm/huge_memory.c | 6 +++--- mm/truncate.c | 31 ++++++++++++++++++++++++++++++- 3 files changed, 69 insertions(+), 4 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index e1bea54820ff..2bd181142b96 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -341,6 +341,36 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, unsigned int new_order); int min_order_for_split(struct folio *folio); int split_folio_to_list(struct folio *folio, struct list_head *list); +bool uniform_split_supported(struct folio *folio, unsigned int new_order, + bool warns); +bool non_uniform_split_supported(struct folio *folio, unsigned int new_order, + bool warns); +int folio_split(struct folio *folio, unsigned int new_order, struct page *page, + struct list_head *list); +/* + * try_folio_split - try to split a @folio at @page using non uniform split. + * @folio: folio to be split + * @page: split to order-0 at the given page + * @list: store the after-split folios + * + * Try to split a @folio at @page using non uniform split to order-0, if + * non uniform split is not supported, fall back to uniform split. + * + * Return: 0: split is successful, otherwise split failed. + */ +static inline int try_folio_split(struct folio *folio, struct page *page, + struct list_head *list) +{ + int ret = min_order_for_split(folio); + + if (ret < 0) + return ret; + + if (!non_uniform_split_supported(folio, 0, false)) + return split_huge_page_to_list_to_order(&folio->page, list, + ret); + return folio_split(folio, ret, page, list); +} static inline int split_huge_page(struct page *page) { struct folio *folio = page_folio(page); @@ -533,6 +563,12 @@ static inline int split_folio_to_list(struct folio *folio, struct list_head *lis return 0; } +static inline int try_folio_split(struct folio *folio, struct page *page, + struct list_head *list) +{ + return 0; +} + static inline void deferred_split_folio(struct folio *folio, bool partially_mapped) {} #define split_huge_pmd(__vma, __pmd, __address) \ do { } while (0) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 9c257c4006f5..e98d322c3ac9 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3523,7 +3523,7 @@ static int __split_unmapped_folio(struct folio *folio, int new_order, return ret; } -static bool non_uniform_split_supported(struct folio *folio, unsigned int new_order, +bool non_uniform_split_supported(struct folio *folio, unsigned int new_order, bool warns) { if (folio_test_anon(folio)) { @@ -3555,7 +3555,7 @@ static bool non_uniform_split_supported(struct folio *folio, unsigned int new_or } /* See comments in non_uniform_split_supported() */ -static bool uniform_split_supported(struct folio *folio, unsigned int new_order, +bool uniform_split_supported(struct folio *folio, unsigned int new_order, bool warns) { if (folio_test_anon(folio)) { @@ -3869,7 +3869,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, * * After split, folio is left locked for caller. */ -static int folio_split(struct folio *folio, unsigned int new_order, +int folio_split(struct folio *folio, unsigned int new_order, struct page *split_at, struct list_head *list) { return __folio_split(folio, new_order, split_at, &folio->page, list, diff --git a/mm/truncate.c b/mm/truncate.c index e2e115adfbc5..09948178f2f4 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -178,6 +178,7 @@ bool truncate_inode_partial_folio(struct folio *folio, loff_t start, loff_t end) { loff_t pos = folio_pos(folio); unsigned int offset, length; + struct page *split_at, *split_at2; if (pos < start) offset = start - pos; @@ -207,8 +208,36 @@ bool truncate_inode_partial_folio(struct folio *folio, loff_t start, loff_t end) folio_invalidate(folio, offset, length); if (!folio_test_large(folio)) return true; - if (split_folio(folio) == 0) + + split_at = folio_page(folio, PAGE_ALIGN_DOWN(offset) / PAGE_SIZE); + split_at2 = folio_page(folio, + PAGE_ALIGN_DOWN(offset + length) / PAGE_SIZE); + + if (!try_folio_split(folio, split_at, NULL)) { + /* + * try to split at offset + length to make sure folios within + * the range can be dropped, especially to avoid memory waste + * for shmem truncate + */ + struct folio *folio2 = page_folio(split_at2); + + if (!folio_try_get(folio2)) + goto no_split; + + if (!folio_test_large(folio2)) + goto out; + + if (!folio_trylock(folio2)) + goto out; + + /* split result does not matter here */ + try_folio_split(folio2, split_at2, NULL); + folio_unlock(folio2); +out: + folio_put(folio2); +no_split: return true; + } if (folio_test_dirty(folio)) return false; truncate_inode_folio(folio->mapping, folio);