From patchwork Mon Jun 7 20:42:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Sierra Guiza, Alejandro (Alex)" X-Patchwork-Id: 12304719 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,MSGID_FROM_MTA_HEADER,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 E1979C48BCF for ; Mon, 7 Jun 2021 20:43:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 85AA361108 for ; Mon, 7 Jun 2021 20:43:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85AA361108 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amd.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 276956B0073; Mon, 7 Jun 2021 16:43:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1D9BC6B0074; Mon, 7 Jun 2021 16:43:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EF94C6B0075; Mon, 7 Jun 2021 16:43:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0023.hostedemail.com [216.40.44.23]) by kanga.kvack.org (Postfix) with ESMTP id B652B6B0073 for ; Mon, 7 Jun 2021 16:43:07 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 5F5FF8790 for ; Mon, 7 Jun 2021 20:43:07 +0000 (UTC) X-FDA: 78228102414.21.B8A1655 Received: from NAM10-MW2-obe.outbound.protection.outlook.com (mail-mw2nam10on2048.outbound.protection.outlook.com [40.107.94.48]) by imf21.hostedemail.com (Postfix) with ESMTP id 677F4E017CF5 for ; Mon, 7 Jun 2021 20:42:47 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=krY6ucNhjOEYKRrS9FIyD6ZYYusuxaRq3Pns9Y4prZ3TVp3nctfzk28u5TJujGYdqpjoWSn3Bah57zgAv9n73WcCfnl1nWNA6Yw/eQ9PxnapVaD05gxpFhwVwn+AQNTj8YdD6TyqvR6KIBSFtF0YNbP2l0pAcEgs7lkQfA0NFKNThRT6LShy85+tvPy912gMW+Ga6WRwJ9k9xyUBWhoQFfqPcL1lB3XAj+vFxXhZZzvFj+2HMiNWbhi6gLdZupFNHLH8p7oMZeKNGHR7Fq3wOxsw0Tdu4APOShXvxmLhlKjg1D//tm7AtuDiNrcSAJK2qVlESl/IiYXeitIHxk9BUQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=+Y6by+cj+a5kSxkkXciWS4gzS7j6Iew/i6e/lGV+t/Q=; b=K6A69cgfdFLv/yZfYbEKr4DVNpNU11sQCWvjX1oFe8mmC5purFkFvyuJmEDjwM2/2Zl6LTwuOvo+KSao8pxJcYb/vC7B6fbjGbp0/rpOduTQanWRGWE3A5ZQBPgIW3YBWNdhdYDsomL9X2adbOuJM6kW8lIpFjUDrTwuKr+RmLOg9hIxNb2LPLRt/lnOiO6cIDhaLggxPbrRRsp07z02BjdmLL34q4cJtplv4QxJYScN+uff6CSkpzayWomaAMQ932qfmcwtBIHrsvkIdfCiKCN6bb5uca2nfHyxpnwFIVkJbnZREdQ99OfBELBZqpTsdLTg/mGvbV4E2lK1ar8jyw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=+Y6by+cj+a5kSxkkXciWS4gzS7j6Iew/i6e/lGV+t/Q=; b=qLMqc15xlGSy7lyO+vyKDMSOKw0orVyPzoI/jvaZs1SCzd+dnvkyT6CTuHH/5JIVblV08jIgJzx5jdiTM9FTKAYD/DcEFsm5wpeeZisnFtj58EgR9JJ6Tzj2gdU6q2wrTZ5SbRKkNqHd0zo0koSoWuR2+T0oE8g1t9PJaGYML2k= Received: from SA0PR12MB4430.namprd12.prod.outlook.com (2603:10b6:806:70::20) by SA0PR12MB4495.namprd12.prod.outlook.com (2603:10b6:806:70::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4195.20; Mon, 7 Jun 2021 20:42:40 +0000 Received: from SA0PR12MB4430.namprd12.prod.outlook.com ([fe80::5ce6:fed4:e00f:27e4]) by SA0PR12MB4430.namprd12.prod.outlook.com ([fe80::5ce6:fed4:e00f:27e4%5]) with mapi id 15.20.4195.030; Mon, 7 Jun 2021 20:42:40 +0000 From: Alex Sierra To: akpm@linux-foundation.org, Felix.Kuehling@amd.com, linux-mm@kvack.org, rcampbell@nvidia.com Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, hch@lst.de, jgg@nvidia.com, jglisse@redhat.com Subject: [RFC PATCH v2 2/8] mm: remove extra ZONE_DEVICE struct page refcount Date: Mon, 7 Jun 2021 15:42:20 -0500 Message-Id: <20210607204226.7743-3-alex.sierra@amd.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210607204226.7743-1-alex.sierra@amd.com> References: <20210607204226.7743-1-alex.sierra@amd.com> X-Originating-IP: [165.204.78.1] X-ClientProxiedBy: SN4PR0601CA0018.namprd06.prod.outlook.com (2603:10b6:803:2f::28) To SA0PR12MB4430.namprd12.prod.outlook.com (2603:10b6:806:70::20) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from alex-MS-7B09.amd.com (165.204.78.1) by SN4PR0601CA0018.namprd06.prod.outlook.com (2603:10b6:803:2f::28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4195.22 via Frontend Transport; Mon, 7 Jun 2021 20:42:40 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 03884221-d9dd-4b52-883e-08d929f4cb00 X-MS-TrafficTypeDiagnostic: SA0PR12MB4495: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:6430; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; 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:SA0PR12MB4430.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(376002)(136003)(346002)(366004)(39860400002)(396003)(956004)(2616005)(30864003)(6666004)(38100700002)(316002)(26005)(5660300002)(1076003)(2906002)(6486002)(66556008)(66476007)(186003)(4326008)(16526019)(66946007)(44832011)(52116002)(7696005)(478600001)(83380400001)(36756003)(8676002)(38350700002)(86362001)(8936002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: 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 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 03884221-d9dd-4b52-883e-08d929f4cb00 X-MS-Exchange-CrossTenant-AuthSource: SA0PR12MB4430.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Jun 2021 20:42:40.5827 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Cj+unjeU6ncObsiBzeD09ZKhIH/EwYCylrdLsCydnwxWqebGtmV2j7nz5jLytAcQfBkTcvde7wJ2nffXLNZ1gw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA0PR12MB4495 Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=amd.com header.s=selector1 header.b=qLMqc15x; spf=pass (imf21.hostedemail.com: domain of Alex.Sierra@amd.com designates 40.107.94.48 as permitted sender) smtp.mailfrom=Alex.Sierra@amd.com; dmarc=pass (policy=quarantine) header.from=amd.com X-Stat-Signature: 7np9du1c9zk1rq5fh1x94wjbi69hs3zd X-Rspamd-Queue-Id: 677F4E017CF5 X-Rspamd-Server: rspam06 X-HE-Tag: 1623098567-586797 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: From: Ralph Campbell ZONE_DEVICE struct pages have an extra reference count that complicates the code for put_page() and several places in the kernel that need to check the reference count to see that a page is not being used (gup, compaction, migration, etc.). Clean up the code so the reference count doesn't need to be treated specially for ZONE_DEVICE. v2: AS: merged this patch in linux 5.11 version Signed-off-by: Ralph Campbell Signed-off-by: Alex Sierra --- arch/powerpc/kvm/book3s_hv_uvmem.c | 2 +- drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +- fs/dax.c | 4 +- include/linux/dax.h | 2 +- include/linux/memremap.h | 7 +-- include/linux/mm.h | 44 ----------------- lib/test_hmm.c | 2 +- mm/internal.h | 8 +++ mm/memremap.c | 68 +++++++------------------- mm/migrate.c | 5 -- mm/page_alloc.c | 3 ++ mm/swap.c | 45 ++--------------- 12 files changed, 45 insertions(+), 147 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 84e5a2dc8be5..acee67710620 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -711,7 +711,7 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm) dpage = pfn_to_page(uvmem_pfn); dpage->zone_device_data = pvt; - get_page(dpage); + init_page_count(dpage); lock_page(dpage); return dpage; out_clear: diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index 92987daa5e17..8bc7120e1216 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c @@ -324,7 +324,7 @@ nouveau_dmem_page_alloc_locked(struct nouveau_drm *drm) return NULL; } - get_page(page); + init_page_count(page); lock_page(page); return page; } diff --git a/fs/dax.c b/fs/dax.c index 321f4ddc6643..7b4c6b35b098 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -560,14 +560,14 @@ static void *grab_mapping_entry(struct xa_state *xas, /** * dax_layout_busy_page_range - find first pinned page in @mapping - * @mapping: address space to scan for a page with ref count > 1 + * @mapping: address space to scan for a page with ref count > 0 * @start: Starting offset. Page containing 'start' is included. * @end: End offset. Page containing 'end' is included. If 'end' is LLONG_MAX, * pages from 'start' till the end of file are included. * * DAX requires ZONE_DEVICE mapped pages. These pages are never * 'onlined' to the page allocator so they are considered idle when - * page->count == 1. A filesystem uses this interface to determine if + * page->count == 0. A filesystem uses this interface to determine if * any page in the mapping is busy, i.e. for DMA, or other * get_user_pages() usages. * diff --git a/include/linux/dax.h b/include/linux/dax.h index 8909a91cd381..9487dc06b220 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -245,7 +245,7 @@ static inline bool dax_mapping(struct address_space *mapping) static inline bool dax_layout_is_idle_page(struct page *page) { - return page_ref_count(page) == 1; + return page_ref_count(page) == 0; } #define dax_wait_page(_inode, _page, _wait_cb) \ diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 79c49e7f5c30..327f32427d21 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -66,9 +66,10 @@ enum memory_type { struct dev_pagemap_ops { /* - * Called once the page refcount reaches 1. (ZONE_DEVICE pages never - * reach 0 refcount unless there is a refcount bug. This allows the - * device driver to implement its own memory management.) + * Called once the page refcount reaches 0. The reference count + * should be reset to one with init_page_count(page) before reusing + * the page. This allows the device driver to implement its own + * memory management. */ void (*page_free)(struct page *page); diff --git a/include/linux/mm.h b/include/linux/mm.h index c9900aedc195..d8d79bb94be8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1117,39 +1117,6 @@ static inline bool is_zone_device_page(const struct page *page) } #endif -#ifdef CONFIG_DEV_PAGEMAP_OPS -void free_devmap_managed_page(struct page *page); -DECLARE_STATIC_KEY_FALSE(devmap_managed_key); - -static inline bool page_is_devmap_managed(struct page *page) -{ - if (!static_branch_unlikely(&devmap_managed_key)) - return false; - if (!is_zone_device_page(page)) - return false; - switch (page->pgmap->type) { - case MEMORY_DEVICE_PRIVATE: - case MEMORY_DEVICE_FS_DAX: - return true; - default: - break; - } - return false; -} - -void put_devmap_managed_page(struct page *page); - -#else /* CONFIG_DEV_PAGEMAP_OPS */ -static inline bool page_is_devmap_managed(struct page *page) -{ - return false; -} - -static inline void put_devmap_managed_page(struct page *page) -{ -} -#endif /* CONFIG_DEV_PAGEMAP_OPS */ - static inline bool is_device_private_page(const struct page *page) { return IS_ENABLED(CONFIG_DEV_PAGEMAP_OPS) && @@ -1196,17 +1163,6 @@ static inline void put_page(struct page *page) { page = compound_head(page); - /* - * For devmap managed pages we need to catch refcount transition from - * 2 to 1, when refcount reach one it means the page is free and we - * need to inform the device driver through callback. See - * include/linux/memremap.h and HMM for details. - */ - if (page_is_devmap_managed(page)) { - put_devmap_managed_page(page); - return; - } - if (put_page_testzero(page)) __put_page(page); } diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 80a78877bd93..6998f10350ea 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -561,7 +561,7 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice) } dpage->zone_device_data = rpage; - get_page(dpage); + init_page_count(dpage); lock_page(dpage); return dpage; diff --git a/mm/internal.h b/mm/internal.h index 25d2b2439f19..d3e58746f2d2 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -623,4 +623,12 @@ struct migration_target_control { gfp_t gfp_mask; }; +#ifdef CONFIG_DEV_PAGEMAP_OPS +void free_zone_device_page(struct page *page); +#else +static inline void free_zone_device_page(struct page *page) +{ +} +#endif + #endif /* __MM_INTERNAL_H */ diff --git a/mm/memremap.c b/mm/memremap.c index 16b2fb482da1..614b3d600e95 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -12,6 +12,7 @@ #include #include #include +#include "internal.h" static DEFINE_XARRAY(pgmap_array); @@ -37,32 +38,6 @@ unsigned long memremap_compat_align(void) EXPORT_SYMBOL_GPL(memremap_compat_align); #endif -#ifdef CONFIG_DEV_PAGEMAP_OPS -DEFINE_STATIC_KEY_FALSE(devmap_managed_key); -EXPORT_SYMBOL(devmap_managed_key); - -static void devmap_managed_enable_put(struct dev_pagemap *pgmap) -{ - if (pgmap->type == MEMORY_DEVICE_PRIVATE || - pgmap->type == MEMORY_DEVICE_FS_DAX) - static_branch_dec(&devmap_managed_key); -} - -static void devmap_managed_enable_get(struct dev_pagemap *pgmap) -{ - if (pgmap->type == MEMORY_DEVICE_PRIVATE || - pgmap->type == MEMORY_DEVICE_FS_DAX) - static_branch_inc(&devmap_managed_key); -} -#else -static void devmap_managed_enable_get(struct dev_pagemap *pgmap) -{ -} -static void devmap_managed_enable_put(struct dev_pagemap *pgmap) -{ -} -#endif /* CONFIG_DEV_PAGEMAP_OPS */ - static void pgmap_array_delete(struct range *range) { xa_store_range(&pgmap_array, PHYS_PFN(range->start), PHYS_PFN(range->end), @@ -87,16 +62,6 @@ static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id) return (range->start + range_len(range)) >> PAGE_SHIFT; } -static unsigned long pfn_next(unsigned long pfn) -{ - if (pfn % 1024 == 0) - cond_resched(); - return pfn + 1; -} - -#define for_each_device_pfn(pfn, map, i) \ - for (pfn = pfn_first(map, i); pfn < pfn_end(map, i); pfn = pfn_next(pfn)) - static void dev_pagemap_kill(struct dev_pagemap *pgmap) { if (pgmap->ops && pgmap->ops->kill) @@ -152,20 +117,18 @@ static void pageunmap_range(struct dev_pagemap *pgmap, int range_id) void memunmap_pages(struct dev_pagemap *pgmap) { - unsigned long pfn; int i; dev_pagemap_kill(pgmap); for (i = 0; i < pgmap->nr_range; i++) - for_each_device_pfn(pfn, pgmap, i) - put_page(pfn_to_page(pfn)); + percpu_ref_put_many(pgmap->ref, pfn_end(pgmap, i) - + pfn_first(pgmap, i)); dev_pagemap_cleanup(pgmap); for (i = 0; i < pgmap->nr_range; i++) pageunmap_range(pgmap, i); WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n"); - devmap_managed_enable_put(pgmap); } EXPORT_SYMBOL_GPL(memunmap_pages); @@ -361,8 +324,6 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) } } - devmap_managed_enable_get(pgmap); - /* * Clear the pgmap nr_range as it will be incremented for each * successfully processed range. This communicates how many @@ -477,16 +438,10 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn, EXPORT_SYMBOL_GPL(get_dev_pagemap); #ifdef CONFIG_DEV_PAGEMAP_OPS -void free_devmap_managed_page(struct page *page) +static void free_device_private_page(struct page *page) { - /* notify page idle for dax */ - if (!is_device_private_page(page)) { - wake_up_var(&page->_refcount); - return; - } __ClearPageWaiters(page); - mem_cgroup_uncharge(page); /* @@ -513,4 +468,19 @@ void free_devmap_managed_page(struct page *page) page->mapping = NULL; page->pgmap->ops->page_free(page); } + +void free_zone_device_page(struct page *page) +{ + switch (page->pgmap->type) { + case MEMORY_DEVICE_FS_DAX: + /* notify page idle */ + wake_up_var(&page->_refcount); + return; + case MEMORY_DEVICE_PRIVATE: + free_device_private_page(page); + return; + default: + return; + } +} #endif /* CONFIG_DEV_PAGEMAP_OPS */ diff --git a/mm/migrate.c b/mm/migrate.c index 20ca887ea769..8c2430d3e77b 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -376,11 +376,6 @@ static int expected_page_refs(struct address_space *mapping, struct page *page) { int expected_count = 1; - /* - * Device private pages have an extra refcount as they are - * ZONE_DEVICE pages. - */ - expected_count += is_device_private_page(page); if (mapping) expected_count += thp_nr_pages(page) + page_has_private(page); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 519a60d5b6f7..4612c457d0b0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6210,6 +6210,9 @@ void __ref memmap_init_zone_device(struct zone *zone, __init_single_page(page, pfn, zone_idx, nid); + /* ZONE_DEVICE pages start with a zero reference count. */ + set_page_count(page, 0); + /* * Mark page reserved as it will need to wait for onlining * phase for it to be fully associated with a zone. diff --git a/mm/swap.c b/mm/swap.c index 2cca7141470c..0a12af814065 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -114,12 +114,11 @@ static void __put_compound_page(struct page *page) void __put_page(struct page *page) { if (is_zone_device_page(page)) { - put_dev_pagemap(page->pgmap); - /* * The page belongs to the device that created pgmap. Do * not return it to page allocator. */ + free_zone_device_page(page); return; } @@ -878,29 +877,18 @@ void release_pages(struct page **pages, int nr) if (is_huge_zero_page(page)) continue; + if (!put_page_testzero(page)) + continue; + if (is_zone_device_page(page)) { if (lruvec) { unlock_page_lruvec_irqrestore(lruvec, flags); lruvec = NULL; } - /* - * ZONE_DEVICE pages that return 'false' from - * page_is_devmap_managed() do not require special - * processing, and instead, expect a call to - * put_page_testzero(). - */ - if (page_is_devmap_managed(page)) { - put_devmap_managed_page(page); - continue; - } - if (put_page_testzero(page)) - put_dev_pagemap(page->pgmap); + free_zone_device_page(page); continue; } - if (!put_page_testzero(page)) - continue; - if (PageCompound(page)) { if (lruvec) { unlock_page_lruvec_irqrestore(lruvec, flags); @@ -1142,26 +1130,3 @@ void __init swap_setup(void) * _really_ don't want to cluster much more */ } - -#ifdef CONFIG_DEV_PAGEMAP_OPS -void put_devmap_managed_page(struct page *page) -{ - int count; - - if (WARN_ON_ONCE(!page_is_devmap_managed(page))) - return; - - count = page_ref_dec_return(page); - - /* - * devmap page refcounts are 1-based, rather than 0-based: if - * refcount is 1, then the page is free and the refcount is - * stable because nobody holds a reference on the page. - */ - if (count == 1) - free_devmap_managed_page(page); - else if (!count) - __put_page(page); -} -EXPORT_SYMBOL(put_devmap_managed_page); -#endif