From patchwork Thu Feb 4 03:50:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12066221 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 EADCAC4332D for ; Thu, 4 Feb 2021 03:55:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8B2964F67 for ; Thu, 4 Feb 2021 03:55:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231807AbhBDDzP (ORCPT ); Wed, 3 Feb 2021 22:55:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231710AbhBDDzM (ORCPT ); Wed, 3 Feb 2021 22:55:12 -0500 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42F10C06178A for ; Wed, 3 Feb 2021 19:54:05 -0800 (PST) Received: by mail-pj1-x1034.google.com with SMTP id cl8so939027pjb.0 for ; Wed, 03 Feb 2021 19:54:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=hpLIh7IjkIEQZERKyf1F1oHAap3BQrhZ7hsJADdLXO0=; b=LlorOLncd0tpRkfoSl+OjQ6WmrZ/fYB9A8IBayQ0j2j+F14DTiZJOWVi7R/AkrAv1w h6kAc4mDdVbBiLEwebhz/EyBLDPKyZX5RQ6IYkvI02XFpWChlvio2N3mZ1zOCuHEAKCR L4A/FiaSKHYnBzGn1wQVKjj4A09tem3jt0BanH079RnNVfQIHloDsHjyysVHkKTbrkPM Pnc/+quGNddriUnEuM1IYCdc61daYbcYvDnQa4xCqm1mEYXMaG5sGOETEYebY7hpreSf o8PQgZyQX93qGqLnkG4laYq8qxHihUjyrmc/SHhYz2i+7pJLH/8Kp+9uu+rjWYREE0aa 61WA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=hpLIh7IjkIEQZERKyf1F1oHAap3BQrhZ7hsJADdLXO0=; b=MRovwY1NCVAEQHm3NNGj9pRduUY1B9zchLEivLWrsPz22O/iQXG5CQ6Y8hY3dOdvA4 e/nxsvfwYxtIthCelezwoBTCg0hRiN2wD8cW02EQToyP80WaITrjhDDvlsi5HWrj/Pl1 324EMuzlKvxIraOyDaZV3LgpPBdzqi32u8FZWHGiLXXqG37n2SfAzlAArtpMEjXhuTST ZWXOsmiBIZ/Qr2f/EEHJdDG0WOnfvVx6wtfJpCTKCqsEanwTBzqZ1QkdzIcWogdhP33L DcPX3xVakmqQb/pBDQuKgdpxw5Ro5HoV2JeScXAUL0Ud2W63PYvvyrzPGJjAcZ9GpERk +REg== X-Gm-Message-State: AOAM5327TcS0vPllwJvg1sgOIIr7tdmGIdXmeJTnrVXWcAphix4LMuNp 3a4vQ3MvbnNS56jNdTfoVs2Bvw== X-Google-Smtp-Source: ABdhPJzvIpNQGWvNO8AJ2n+1kF+z6XSk3Va1umsyc/s90GDq2+k6GMeuDMv/ok6UBYg6BiQ6TW/AuQ== X-Received: by 2002:a17:90a:5914:: with SMTP id k20mr6284807pji.199.1612410844740; Wed, 03 Feb 2021 19:54:04 -0800 (PST) Received: from localhost.localdomain ([139.177.225.239]) by smtp.gmail.com with ESMTPSA id 9sm3747466pfy.110.2021.02.03.19.53.50 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Feb 2021 19:54:04 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song , Miaohe Lin Subject: [PATCH v14 1/8] mm: memory_hotplug: factor out bootmem core functions to bootmem_info.c Date: Thu, 4 Feb 2021 11:50:36 +0800 Message-Id: <20210204035043.36609-2-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210204035043.36609-1-songmuchun@bytedance.com> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Move bootmem info registration common API to individual bootmem_info.c. And we will use {get,put}_page_bootmem() to initialize the page for the vmemmap pages or free the vmemmap pages to buddy in the later patch. So move them out of CONFIG_MEMORY_HOTPLUG_SPARSE. This is just code movement without any functional change. Signed-off-by: Muchun Song Acked-by: Mike Kravetz Reviewed-by: Oscar Salvador Reviewed-by: David Hildenbrand Reviewed-by: Miaohe Lin --- arch/x86/mm/init_64.c | 3 +- include/linux/bootmem_info.h | 40 +++++++++++++ include/linux/memory_hotplug.h | 27 --------- mm/Makefile | 1 + mm/bootmem_info.c | 124 +++++++++++++++++++++++++++++++++++++++++ mm/memory_hotplug.c | 116 -------------------------------------- mm/sparse.c | 1 + 7 files changed, 168 insertions(+), 144 deletions(-) create mode 100644 include/linux/bootmem_info.h create mode 100644 mm/bootmem_info.c diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index b5a3fa4033d3..0a45f062826e 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -1571,7 +1572,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, return err; } -#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE) +#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE void register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page, unsigned long nr_pages) { diff --git a/include/linux/bootmem_info.h b/include/linux/bootmem_info.h new file mode 100644 index 000000000000..4ed6dee1adc9 --- /dev/null +++ b/include/linux/bootmem_info.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_BOOTMEM_INFO_H +#define __LINUX_BOOTMEM_INFO_H + +#include + +/* + * Types for free bootmem stored in page->lru.next. These have to be in + * some random range in unsigned long space for debugging purposes. + */ +enum { + MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 12, + SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE, + MIX_SECTION_INFO, + NODE_INFO, + MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO, +}; + +#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE +void __init register_page_bootmem_info_node(struct pglist_data *pgdat); + +void get_page_bootmem(unsigned long info, struct page *page, + unsigned long type); +void put_page_bootmem(struct page *page); +#else +static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) +{ +} + +static inline void put_page_bootmem(struct page *page) +{ +} + +static inline void get_page_bootmem(unsigned long info, struct page *page, + unsigned long type) +{ +} +#endif + +#endif /* __LINUX_BOOTMEM_INFO_H */ diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 7288aa5ef73b..96659a8b9d02 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -18,18 +18,6 @@ struct vmem_altmap; #ifdef CONFIG_MEMORY_HOTPLUG struct page *pfn_to_online_page(unsigned long pfn); -/* - * Types for free bootmem stored in page->lru.next. These have to be in - * some random range in unsigned long space for debugging purposes. - */ -enum { - MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 12, - SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE, - MIX_SECTION_INFO, - NODE_INFO, - MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO, -}; - /* Types for control the zone type of onlined and offlined memory */ enum { /* Offline the memory. */ @@ -210,17 +198,6 @@ static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat) #endif /* CONFIG_NUMA */ #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */ -#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE -extern void __init register_page_bootmem_info_node(struct pglist_data *pgdat); -#else -static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) -{ -} -#endif -extern void put_page_bootmem(struct page *page); -extern void get_page_bootmem(unsigned long ingo, struct page *page, - unsigned long type); - void get_online_mems(void); void put_online_mems(void); @@ -248,10 +225,6 @@ static inline void zone_span_writelock(struct zone *zone) {} static inline void zone_span_writeunlock(struct zone *zone) {} static inline void zone_seqlock_init(struct zone *zone) {} -static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) -{ -} - static inline int try_online_node(int nid) { return 0; diff --git a/mm/Makefile b/mm/Makefile index b2a564eec27f..ce4ddbe4461d 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -83,6 +83,7 @@ obj-$(CONFIG_SLUB) += slub.o obj-$(CONFIG_KASAN) += kasan/ obj-$(CONFIG_KFENCE) += kfence/ obj-$(CONFIG_FAILSLAB) += failslab.o +obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) += bootmem_info.o obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o obj-$(CONFIG_MEMTEST) += memtest.o obj-$(CONFIG_MIGRATION) += migrate.o diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c new file mode 100644 index 000000000000..fcab5a3f8cc0 --- /dev/null +++ b/mm/bootmem_info.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/mm/bootmem_info.c + * + * Copyright (C) + */ +#include +#include +#include +#include +#include + +void get_page_bootmem(unsigned long info, struct page *page, unsigned long type) +{ + page->freelist = (void *)type; + SetPagePrivate(page); + set_page_private(page, info); + page_ref_inc(page); +} + +void put_page_bootmem(struct page *page) +{ + unsigned long type; + + type = (unsigned long) page->freelist; + BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || + type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); + + if (page_ref_dec_return(page) == 1) { + page->freelist = NULL; + ClearPagePrivate(page); + set_page_private(page, 0); + INIT_LIST_HEAD(&page->lru); + free_reserved_page(page); + } +} + +#ifndef CONFIG_SPARSEMEM_VMEMMAP +static void register_page_bootmem_info_section(unsigned long start_pfn) +{ + unsigned long mapsize, section_nr, i; + struct mem_section *ms; + struct page *page, *memmap; + struct mem_section_usage *usage; + + section_nr = pfn_to_section_nr(start_pfn); + ms = __nr_to_section(section_nr); + + /* Get section's memmap address */ + memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); + + /* + * Get page for the memmap's phys address + * XXX: need more consideration for sparse_vmemmap... + */ + page = virt_to_page(memmap); + mapsize = sizeof(struct page) * PAGES_PER_SECTION; + mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; + + /* remember memmap's page */ + for (i = 0; i < mapsize; i++, page++) + get_page_bootmem(section_nr, page, SECTION_INFO); + + usage = ms->usage; + page = virt_to_page(usage); + + mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; + + for (i = 0; i < mapsize; i++, page++) + get_page_bootmem(section_nr, page, MIX_SECTION_INFO); + +} +#else /* CONFIG_SPARSEMEM_VMEMMAP */ +static void register_page_bootmem_info_section(unsigned long start_pfn) +{ + unsigned long mapsize, section_nr, i; + struct mem_section *ms; + struct page *page, *memmap; + struct mem_section_usage *usage; + + section_nr = pfn_to_section_nr(start_pfn); + ms = __nr_to_section(section_nr); + + memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); + + register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); + + usage = ms->usage; + page = virt_to_page(usage); + + mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; + + for (i = 0; i < mapsize; i++, page++) + get_page_bootmem(section_nr, page, MIX_SECTION_INFO); +} +#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ + +void __init register_page_bootmem_info_node(struct pglist_data *pgdat) +{ + unsigned long i, pfn, end_pfn, nr_pages; + int node = pgdat->node_id; + struct page *page; + + nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; + page = virt_to_page(pgdat); + + for (i = 0; i < nr_pages; i++, page++) + get_page_bootmem(node, page, NODE_INFO); + + pfn = pgdat->node_start_pfn; + end_pfn = pgdat_end_pfn(pgdat); + + /* register section info */ + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + /* + * Some platforms can assign the same pfn to multiple nodes - on + * node0 as well as nodeN. To avoid registering a pfn against + * multiple nodes we check that this pfn does not already + * reside in some other nodes. + */ + if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) + register_page_bootmem_info_section(pfn); + } +} diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 5ba51a8bdaeb..a2a72b617040 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -144,122 +144,6 @@ static void release_memory_resource(struct resource *res) } #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE -void get_page_bootmem(unsigned long info, struct page *page, - unsigned long type) -{ - page->freelist = (void *)type; - SetPagePrivate(page); - set_page_private(page, info); - page_ref_inc(page); -} - -void put_page_bootmem(struct page *page) -{ - unsigned long type; - - type = (unsigned long) page->freelist; - BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || - type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); - - if (page_ref_dec_return(page) == 1) { - page->freelist = NULL; - ClearPagePrivate(page); - set_page_private(page, 0); - INIT_LIST_HEAD(&page->lru); - free_reserved_page(page); - } -} - -#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE -#ifndef CONFIG_SPARSEMEM_VMEMMAP -static void register_page_bootmem_info_section(unsigned long start_pfn) -{ - unsigned long mapsize, section_nr, i; - struct mem_section *ms; - struct page *page, *memmap; - struct mem_section_usage *usage; - - section_nr = pfn_to_section_nr(start_pfn); - ms = __nr_to_section(section_nr); - - /* Get section's memmap address */ - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - - /* - * Get page for the memmap's phys address - * XXX: need more consideration for sparse_vmemmap... - */ - page = virt_to_page(memmap); - mapsize = sizeof(struct page) * PAGES_PER_SECTION; - mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; - - /* remember memmap's page */ - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, SECTION_INFO); - - usage = ms->usage; - page = virt_to_page(usage); - - mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; - - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, MIX_SECTION_INFO); - -} -#else /* CONFIG_SPARSEMEM_VMEMMAP */ -static void register_page_bootmem_info_section(unsigned long start_pfn) -{ - unsigned long mapsize, section_nr, i; - struct mem_section *ms; - struct page *page, *memmap; - struct mem_section_usage *usage; - - section_nr = pfn_to_section_nr(start_pfn); - ms = __nr_to_section(section_nr); - - memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - - register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); - - usage = ms->usage; - page = virt_to_page(usage); - - mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; - - for (i = 0; i < mapsize; i++, page++) - get_page_bootmem(section_nr, page, MIX_SECTION_INFO); -} -#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ - -void __init register_page_bootmem_info_node(struct pglist_data *pgdat) -{ - unsigned long i, pfn, end_pfn, nr_pages; - int node = pgdat->node_id; - struct page *page; - - nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; - page = virt_to_page(pgdat); - - for (i = 0; i < nr_pages; i++, page++) - get_page_bootmem(node, page, NODE_INFO); - - pfn = pgdat->node_start_pfn; - end_pfn = pgdat_end_pfn(pgdat); - - /* register section info */ - for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - /* - * Some platforms can assign the same pfn to multiple nodes - on - * node0 as well as nodeN. To avoid registering a pfn against - * multiple nodes we check that this pfn does not already - * reside in some other nodes. - */ - if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) - register_page_bootmem_info_section(pfn); - } -} -#endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ - static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, const char *reason) { diff --git a/mm/sparse.c b/mm/sparse.c index 7bd23f9d6cef..87676bf3af40 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -13,6 +13,7 @@ #include #include #include +#include #include "internal.h" #include From patchwork Thu Feb 4 03:50:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12066219 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 43D7AC433E0 for ; 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Wed, 03 Feb 2021 19:54:17 -0800 (PST) Received: from localhost.localdomain ([139.177.225.239]) by smtp.gmail.com with ESMTPSA id 9sm3747466pfy.110.2021.02.03.19.54.05 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Feb 2021 19:54:16 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v14 2/8] mm: hugetlb: introduce a new config HUGETLB_PAGE_FREE_VMEMMAP Date: Thu, 4 Feb 2021 11:50:37 +0800 Message-Id: <20210204035043.36609-3-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210204035043.36609-1-songmuchun@bytedance.com> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The option HUGETLB_PAGE_FREE_VMEMMAP allows for the freeing of some vmemmap pages associated with pre-allocated HugeTLB pages. For example, on X86_64 6 vmemmap pages of size 4KB each can be saved for each 2MB HugeTLB page. 4094 vmemmap pages of size 4KB each can be saved for each 1GB HugeTLB page. When a HugeTLB page is allocated or freed, the vmemmap array representing the range associated with the page will need to be remapped. When a page is allocated, vmemmap pages are freed after remapping. When a page is freed, previously discarded vmemmap pages must be allocated before remapping. The config option is introduced early so that supporting code can be written to depend on the option. The initial version of the code only provides support for x86-64. Like other code which frees vmemmap, this config option depends on HAVE_BOOTMEM_INFO_NODE. The routine register_page_bootmem_info() is used to register bootmem info. Therefore, make sure register_page_bootmem_info is enabled if HUGETLB_PAGE_FREE_VMEMMAP is defined. Signed-off-by: Muchun Song Reviewed-by: Oscar Salvador Acked-by: Mike Kravetz Reviewed-by: Miaohe Lin --- arch/x86/mm/init_64.c | 2 +- fs/Kconfig | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 0a45f062826e..0435bee2e172 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1225,7 +1225,7 @@ static struct kcore_list kcore_vsyscall; static void __init register_page_bootmem_info(void) { -#ifdef CONFIG_NUMA +#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP) int i; for_each_online_node(i) diff --git a/fs/Kconfig b/fs/Kconfig index 97e7b77c9309..de87f234f1e9 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -237,6 +237,12 @@ config HUGETLBFS config HUGETLB_PAGE def_bool HUGETLBFS +config HUGETLB_PAGE_FREE_VMEMMAP + def_bool HUGETLB_PAGE + depends on X86_64 + depends on SPARSEMEM_VMEMMAP + depends on HAVE_BOOTMEM_INFO_NODE + config MEMFD_CREATE def_bool TMPFS || HUGETLBFS From patchwork Thu Feb 4 03:50:38 2021 Content-Type: text/plain; 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Wed, 03 Feb 2021 19:54:29 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v14 3/8] mm: hugetlb: free the vmemmap pages associated with each HugeTLB page Date: Thu, 4 Feb 2021 11:50:38 +0800 Message-Id: <20210204035043.36609-4-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210204035043.36609-1-songmuchun@bytedance.com> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Every HugeTLB has more than one struct page structure. We __know__ that we only use the first 4(HUGETLB_CGROUP_MIN_ORDER) struct page structures to store metadata associated with each HugeTLB. There are a lot of struct page structures associated with each HugeTLB page. For tail pages, the value of compound_head is the same. So we can reuse first page of tail page structures. We map the virtual addresses of the remaining pages of tail page structures to the first tail page struct, and then free these page frames. Therefore, we need to reserve two pages as vmemmap areas. When we allocate a HugeTLB page from the buddy, we can free some vmemmap pages associated with each HugeTLB page. It is more appropriate to do it in the prep_new_huge_page(). The free_vmemmap_pages_per_hpage(), which indicates how many vmemmap pages associated with a HugeTLB page can be freed, returns zero for now, which means the feature is disabled. We will enable it once all the infrastructure is there. Signed-off-by: Muchun Song Reviewed-by: Oscar Salvador --- include/linux/bootmem_info.h | 27 +++++- include/linux/mm.h | 3 + mm/Makefile | 1 + mm/hugetlb.c | 3 + mm/hugetlb_vmemmap.c | 219 +++++++++++++++++++++++++++++++++++++++++++ mm/hugetlb_vmemmap.h | 20 ++++ mm/sparse-vmemmap.c | 207 ++++++++++++++++++++++++++++++++++++++++ 7 files changed, 479 insertions(+), 1 deletion(-) create mode 100644 mm/hugetlb_vmemmap.c create mode 100644 mm/hugetlb_vmemmap.h diff --git a/include/linux/bootmem_info.h b/include/linux/bootmem_info.h index 4ed6dee1adc9..ec03a624dfa2 100644 --- a/include/linux/bootmem_info.h +++ b/include/linux/bootmem_info.h @@ -2,7 +2,7 @@ #ifndef __LINUX_BOOTMEM_INFO_H #define __LINUX_BOOTMEM_INFO_H -#include +#include /* * Types for free bootmem stored in page->lru.next. These have to be in @@ -22,6 +22,27 @@ void __init register_page_bootmem_info_node(struct pglist_data *pgdat); void get_page_bootmem(unsigned long info, struct page *page, unsigned long type); void put_page_bootmem(struct page *page); + +/* + * Any memory allocated via the memblock allocator and not via the + * buddy will be marked reserved already in the memmap. For those + * pages, we can call this function to free it to buddy allocator. + */ +static inline void free_bootmem_page(struct page *page) +{ + unsigned long magic = (unsigned long)page->freelist; + + /* + * The reserve_bootmem_region sets the reserved flag on bootmem + * pages. + */ + VM_BUG_ON_PAGE(page_ref_count(page) != 2, page); + + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) + put_page_bootmem(page); + else + VM_BUG_ON_PAGE(1, page); +} #else static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) { @@ -35,6 +56,10 @@ static inline void get_page_bootmem(unsigned long info, struct page *page, unsigned long type) { } + +static inline void free_bootmem_page(struct page *page) +{ +} #endif #endif /* __LINUX_BOOTMEM_INFO_H */ diff --git a/include/linux/mm.h b/include/linux/mm.h index a608feb0d42e..d7dddf334779 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2979,6 +2979,9 @@ static inline void print_vma_addr(char *prefix, unsigned long rip) } #endif +void vmemmap_remap_free(unsigned long start, unsigned long end, + unsigned long reuse); + void *sparse_buffer_alloc(unsigned long size); struct page * __populate_section_memmap(unsigned long pfn, unsigned long nr_pages, int nid, struct vmem_altmap *altmap); diff --git a/mm/Makefile b/mm/Makefile index ce4ddbe4461d..47b250e4c9b2 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -71,6 +71,7 @@ obj-$(CONFIG_FRONTSWAP) += frontswap.o obj-$(CONFIG_ZSWAP) += zswap.o obj-$(CONFIG_HAS_DMA) += dmapool.o obj-$(CONFIG_HUGETLBFS) += hugetlb.o +obj-$(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP) += hugetlb_vmemmap.o obj-$(CONFIG_NUMA) += mempolicy.o obj-$(CONFIG_SPARSEMEM) += sparse.o obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 8c53f3f2e12e..4cfca27c6d32 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -42,6 +42,7 @@ #include #include #include "internal.h" +#include "hugetlb_vmemmap.h" int hugetlb_max_hstate __read_mostly; unsigned int default_hstate_idx; @@ -1462,6 +1463,8 @@ void free_huge_page(struct page *page) static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) { + free_huge_page_vmemmap(h, page); + INIT_LIST_HEAD(&page->lru); set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); set_hugetlb_cgroup(page, NULL); diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c new file mode 100644 index 000000000000..ddd872ab6180 --- /dev/null +++ b/mm/hugetlb_vmemmap.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Free some vmemmap pages of HugeTLB + * + * Copyright (c) 2020, Bytedance. All rights reserved. + * + * Author: Muchun Song + * + * The struct page structures (page structs) are used to describe a physical + * page frame. By default, there is a one-to-one mapping from a page frame to + * it's corresponding page struct. + * + * HugeTLB pages consist of multiple base page size pages and is supported by + * many architectures. See hugetlbpage.rst in the Documentation directory for + * more details. On the x86-64 architecture, HugeTLB pages of size 2MB and 1GB + * are currently supported. Since the base page size on x86 is 4KB, a 2MB + * HugeTLB page consists of 512 base pages and a 1GB HugeTLB page consists of + * 4096 base pages. For each base page, there is a corresponding page struct. + * + * Within the HugeTLB subsystem, only the first 4 page structs are used to + * contain unique information about a HugeTLB page. HUGETLB_CGROUP_MIN_ORDER + * provides this upper limit. The only 'useful' information in the remaining + * page structs is the compound_head field, and this field is the same for all + * tail pages. + * + * By removing redundant page structs for HugeTLB pages, memory can be returned + * to the buddy allocator for other uses. + * + * Different architectures support different HugeTLB pages. For example, the + * following table is the HugeTLB page size supported by x86 and arm64 + * architectures. Because arm64 supports 4k, 16k, and 64k base pages and + * supports contiguous entries, so it supports many kinds of sizes of HugeTLB + * page. + * + * +--------------+-----------+-----------------------------------------------+ + * | Architecture | Page Size | HugeTLB Page Size | + * +--------------+-----------+-----------+-----------+-----------+-----------+ + * | x86-64 | 4KB | 2MB | 1GB | | | + * +--------------+-----------+-----------+-----------+-----------+-----------+ + * | | 4KB | 64KB | 2MB | 32MB | 1GB | + * | +-----------+-----------+-----------+-----------+-----------+ + * | arm64 | 16KB | 2MB | 32MB | 1GB | | + * | +-----------+-----------+-----------+-----------+-----------+ + * | | 64KB | 2MB | 512MB | 16GB | | + * +--------------+-----------+-----------+-----------+-----------+-----------+ + * + * When the system boot up, every HugeTLB page has more than one struct page + * structs which size is (unit: pages): + * + * struct_size = HugeTLB_Size / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE + * + * Where HugeTLB_Size is the size of the HugeTLB page. We know that the size + * of the HugeTLB page is always n times PAGE_SIZE. So we can get the following + * relationship. + * + * HugeTLB_Size = n * PAGE_SIZE + * + * Then, + * + * struct_size = n * PAGE_SIZE / PAGE_SIZE * sizeof(struct page) / PAGE_SIZE + * = n * sizeof(struct page) / PAGE_SIZE + * + * We can use huge mapping at the pud/pmd level for the HugeTLB page. + * + * For the HugeTLB page of the pmd level mapping, then + * + * struct_size = n * sizeof(struct page) / PAGE_SIZE + * = PAGE_SIZE / sizeof(pte_t) * sizeof(struct page) / PAGE_SIZE + * = sizeof(struct page) / sizeof(pte_t) + * = 64 / 8 + * = 8 (pages) + * + * Where n is how many pte entries which one page can contains. So the value of + * n is (PAGE_SIZE / sizeof(pte_t)). + * + * This optimization only supports 64-bit system, so the value of sizeof(pte_t) + * is 8. And this optimization also applicable only when the size of struct page + * is a power of two. In most cases, the size of struct page is 64 bytes (e.g. + * x86-64 and arm64). So if we use pmd level mapping for a HugeTLB page, the + * size of struct page structs of it is 8 page frames which size depends on the + * size of the base page. + * + * For the HugeTLB page of the pud level mapping, then + * + * struct_size = PAGE_SIZE / sizeof(pmd_t) * struct_size(pmd) + * = PAGE_SIZE / 8 * 8 (pages) + * = PAGE_SIZE (pages) + * + * Where the struct_size(pmd) is the size of the struct page structs of a + * HugeTLB page of the pmd level mapping. + * + * E.g.: A 2MB HugeTLB page on x86_64 consists in 8 page frames while 1GB + * HugeTLB page consists in 4096. + * + * Next, we take the pmd level mapping of the HugeTLB page as an example to + * show the internal implementation of this optimization. There are 8 pages + * struct page structs associated with a HugeTLB page which is pmd mapped. + * + * Here is how things look before optimization. + * + * HugeTLB struct pages(8 pages) page frame(8 pages) + * +-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+ + * | | | 0 | -------------> | 0 | + * | | +-----------+ +-----------+ + * | | | 1 | -------------> | 1 | + * | | +-----------+ +-----------+ + * | | | 2 | -------------> | 2 | + * | | +-----------+ +-----------+ + * | | | 3 | -------------> | 3 | + * | | +-----------+ +-----------+ + * | | | 4 | -------------> | 4 | + * | PMD | +-----------+ +-----------+ + * | level | | 5 | -------------> | 5 | + * | mapping | +-----------+ +-----------+ + * | | | 6 | -------------> | 6 | + * | | +-----------+ +-----------+ + * | | | 7 | -------------> | 7 | + * | | +-----------+ +-----------+ + * | | + * | | + * | | + * +-----------+ + * + * The value of page->compound_head is the same for all tail pages. The first + * page of page structs (page 0) associated with the HugeTLB page contains the 4 + * page structs necessary to describe the HugeTLB. The only use of the remaining + * pages of page structs (page 1 to page 7) is to point to page->compound_head. + * Therefore, we can remap pages 2 to 7 to page 1. Only 2 pages of page structs + * will be used for each HugeTLB page. This will allow us to free the remaining + * 6 pages to the buddy allocator. + * + * Here is how things look after remapping. + * + * HugeTLB struct pages(8 pages) page frame(8 pages) + * +-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+ + * | | | 0 | -------------> | 0 | + * | | +-----------+ +-----------+ + * | | | 1 | -------------> | 1 | + * | | +-----------+ +-----------+ + * | | | 2 | ----------------^ ^ ^ ^ ^ ^ + * | | +-----------+ | | | | | + * | | | 3 | ------------------+ | | | | + * | | +-----------+ | | | | + * | | | 4 | --------------------+ | | | + * | PMD | +-----------+ | | | + * | level | | 5 | ----------------------+ | | + * | mapping | +-----------+ | | + * | | | 6 | ------------------------+ | + * | | +-----------+ | + * | | | 7 | --------------------------+ + * | | +-----------+ + * | | + * | | + * | | + * +-----------+ + * + * When a HugeTLB is freed to the buddy system, we should allocate 6 pages for + * vmemmap pages and restore the previous mapping relationship. + * + * For the HugeTLB page of the pud level mapping. It is similar to the former. + * We also can use this approach to free (PAGE_SIZE - 2) vmemmap pages. + * + * Apart from the HugeTLB page of the pmd/pud level mapping, some architectures + * (e.g. aarch64) provides a contiguous bit in the translation table entries + * that hints to the MMU to indicate that it is one of a contiguous set of + * entries that can be cached in a single TLB entry. + * + * The contiguous bit is used to increase the mapping size at the pmd and pte + * (last) level. So this type of HugeTLB page can be optimized only when its + * size of the struct page structs is greater than 2 pages. + */ +#include "hugetlb_vmemmap.h" + +/* + * There are a lot of struct page structures associated with each HugeTLB page. + * For tail pages, the value of compound_head is the same. So we can reuse first + * page of tail page structures. We map the virtual addresses of the remaining + * pages of tail page structures to the first tail page struct, and then free + * these page frames. Therefore, we need to reserve two pages as vmemmap areas. + */ +#define RESERVE_VMEMMAP_NR 2U +#define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) + +/* + * How many vmemmap pages associated with a HugeTLB page that can be freed + * to the buddy allocator. + * + * Todo: Returns zero for now, which means the feature is disabled. We will + * enable it once all the infrastructure is there. + */ +static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) +{ + return 0; +} + +static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) +{ + return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT; +} + +void free_huge_page_vmemmap(struct hstate *h, struct page *head) +{ + unsigned long vmemmap_addr = (unsigned long)head; + unsigned long vmemmap_end, vmemmap_reuse; + + if (!free_vmemmap_pages_per_hpage(h)) + return; + + vmemmap_addr += RESERVE_VMEMMAP_SIZE; + vmemmap_end = vmemmap_addr + free_vmemmap_pages_size_per_hpage(h); + vmemmap_reuse = vmemmap_addr - PAGE_SIZE; + + /* + * Remap the vmemmap virtual address range [@vmemmap_addr, @vmemmap_end) + * to the page which @vmemmap_reuse is mapped to, then free the vmemmap + * pages which the range are mapped to. + */ + vmemmap_remap_free(vmemmap_addr, vmemmap_end, vmemmap_reuse); +} diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h new file mode 100644 index 000000000000..6923f03534d5 --- /dev/null +++ b/mm/hugetlb_vmemmap.h @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Free some vmemmap pages of HugeTLB + * + * Copyright (c) 2020, Bytedance. All rights reserved. + * + * Author: Muchun Song + */ +#ifndef _LINUX_HUGETLB_VMEMMAP_H +#define _LINUX_HUGETLB_VMEMMAP_H +#include + +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP +void free_huge_page_vmemmap(struct hstate *h, struct page *head); +#else +static inline void free_huge_page_vmemmap(struct hstate *h, struct page *head) +{ +} +#endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */ +#endif /* _LINUX_HUGETLB_VMEMMAP_H */ diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 16183d85a7d5..50c1dc00b686 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -27,8 +27,215 @@ #include #include #include +#include +#include + #include #include +#include + +/** + * vmemmap_remap_walk - walk vmemmap page table + * + * @remap_pte: called for each non-empty PTE (lowest-level) entry. + * @reuse_page: the page which is reused for the tail vmemmap pages. + * @reuse_addr: the virtual address of the @reuse_page page. + * @vmemmap_pages: the list head of the vmemmap pages that can be freed. + */ +struct vmemmap_remap_walk { + void (*remap_pte)(pte_t *pte, unsigned long addr, + struct vmemmap_remap_walk *walk); + struct page *reuse_page; + unsigned long reuse_addr; + struct list_head *vmemmap_pages; +}; + +static void vmemmap_pte_range(pmd_t *pmd, unsigned long addr, + unsigned long end, + struct vmemmap_remap_walk *walk) +{ + pte_t *pte; + + pte = pte_offset_kernel(pmd, addr); + + /* + * The reuse_page is found 'first' in table walk before we start + * remapping (which is calling @walk->remap_pte). + */ + if (!walk->reuse_page) { + BUG_ON(pte_none(*pte) || walk->reuse_addr != addr); + + walk->reuse_page = pte_page(*pte++); + /* + * Because the reuse address is part of the range that we are + * walking, skip the reuse address range. + */ + addr += PAGE_SIZE; + } + + for (; addr != end; addr += PAGE_SIZE, pte++) { + BUG_ON(pte_none(*pte)); + + walk->remap_pte(pte, addr, walk); + } +} + +static void vmemmap_pmd_range(pud_t *pud, unsigned long addr, + unsigned long end, + struct vmemmap_remap_walk *walk) +{ + pmd_t *pmd; + unsigned long next; + + pmd = pmd_offset(pud, addr); + do { + BUG_ON(pmd_none(*pmd) || pmd_leaf(*pmd)); + + next = pmd_addr_end(addr, end); + vmemmap_pte_range(pmd, addr, next, walk); + } while (pmd++, addr = next, addr != end); +} + +static void vmemmap_pud_range(p4d_t *p4d, unsigned long addr, + unsigned long end, + struct vmemmap_remap_walk *walk) +{ + pud_t *pud; + unsigned long next; + + pud = pud_offset(p4d, addr); + do { + BUG_ON(pud_none(*pud)); + + next = pud_addr_end(addr, end); + vmemmap_pmd_range(pud, addr, next, walk); + } while (pud++, addr = next, addr != end); +} + +static void vmemmap_p4d_range(pgd_t *pgd, unsigned long addr, + unsigned long end, + struct vmemmap_remap_walk *walk) +{ + p4d_t *p4d; + unsigned long next; + + p4d = p4d_offset(pgd, addr); + do { + BUG_ON(p4d_none(*p4d)); + + next = p4d_addr_end(addr, end); + vmemmap_pud_range(p4d, addr, next, walk); + } while (p4d++, addr = next, addr != end); +} + +static void vmemmap_remap_range(unsigned long start, unsigned long end, + struct vmemmap_remap_walk *walk) +{ + unsigned long addr = start; + unsigned long next; + pgd_t *pgd; + + VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE)); + VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE)); + + pgd = pgd_offset_k(addr); + do { + BUG_ON(pgd_none(*pgd)); + + next = pgd_addr_end(addr, end); + vmemmap_p4d_range(pgd, addr, next, walk); + } while (pgd++, addr = next, addr != end); + + /* + * We do not change the mapping of the vmemmap virtual address range + * [@start, @start + PAGE_SIZE) which belongs to the reuse range. + * So we not need to flush the TLB. + */ + flush_tlb_kernel_range(start + PAGE_SIZE, end); +} + +/* + * Free a vmemmap page. A vmemmap page can be allocated from the memblock + * allocator or buddy allocator. If the PG_reserved flag is set, it means + * that it allocated from the memblock allocator, just free it via the + * free_bootmem_page(). Otherwise, use __free_page(). + */ +static inline void free_vmemmap_page(struct page *page) +{ + if (PageReserved(page)) + free_bootmem_page(page); + else + __free_page(page); +} + +/* Free a list of the vmemmap pages */ +static void free_vmemmap_page_list(struct list_head *list) +{ + struct page *page, *next; + + list_for_each_entry_safe(page, next, list, lru) { + list_del(&page->lru); + free_vmemmap_page(page); + } +} + +static void vmemmap_remap_pte(pte_t *pte, unsigned long addr, + struct vmemmap_remap_walk *walk) +{ + /* + * Remap the tail pages as read-only to catch illegal write operation + * to the tail pages. + */ + pgprot_t pgprot = PAGE_KERNEL_RO; + pte_t entry = mk_pte(walk->reuse_page, pgprot); + struct page *page = pte_page(*pte); + + list_add(&page->lru, walk->vmemmap_pages); + set_pte_at(&init_mm, addr, pte, entry); +} + +/** + * vmemmap_remap_free - remap the vmemmap virtual address range [@start, @end) + * to the page which @reuse is mapped to, then free vmemmap + * which the range are mapped to. + * @start: start address of the vmemmap virtual address range that we want + * to remap. + * @end: end address of the vmemmap virtual address range that we want to + * remap. + * @reuse: reuse address. + * + * Note: This function depends on vmemmap being base page mapped. Please make + * sure that the architecture disables PMD mapping of vmemmap pages when calling + * this function. + */ +void vmemmap_remap_free(unsigned long start, unsigned long end, + unsigned long reuse) +{ + LIST_HEAD(vmemmap_pages); + struct vmemmap_remap_walk walk = { + .remap_pte = vmemmap_remap_pte, + .reuse_addr = reuse, + .vmemmap_pages = &vmemmap_pages, + }; + + /* + * In order to make remapping routine most efficient for the huge pages, + * the routine of vmemmap page table walking has the following rules + * (see more details from the vmemmap_pte_range()): + * + * - The range [@start, @end) and the range [@reuse, @reuse + PAGE_SIZE) + * should be continuous. + * - The @reuse address is part of the range [@reuse, @end) that we are + * walking which is passed to vmemmap_remap_range(). + * - The @reuse address is the first in the complete range. + * + * So we need to make sure that @start and @reuse meet the above rules. + */ + BUG_ON(start - reuse != PAGE_SIZE); + + vmemmap_remap_range(reuse, end, &walk); + free_vmemmap_page_list(&vmemmap_pages); +} /* * Allocate a block of memory to be used to back the virtual memory map From patchwork Thu Feb 4 03:50:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12066225 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 708F7C433E0 for ; Thu, 4 Feb 2021 03:56:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17B7864F5E for ; 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Wed, 03 Feb 2021 19:54:40 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v14 4/8] mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page Date: Thu, 4 Feb 2021 11:50:39 +0800 Message-Id: <20210204035043.36609-5-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210204035043.36609-1-songmuchun@bytedance.com> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org When we free a HugeTLB page to the buddy allocator, we should allocate the vmemmap pages associated with it. But we may cannot allocate vmemmap pages when the system is under memory pressure, in this case, we just refuse to free the HugeTLB page instead of looping forever trying to allocate the pages. Signed-off-by: Muchun Song --- include/linux/mm.h | 2 ++ mm/hugetlb.c | 19 ++++++++++++- mm/hugetlb_vmemmap.c | 30 +++++++++++++++++++++ mm/hugetlb_vmemmap.h | 8 ++++++ mm/sparse-vmemmap.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++- 5 files changed, 132 insertions(+), 2 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index d7dddf334779..33c5911afe18 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2981,6 +2981,8 @@ static inline void print_vma_addr(char *prefix, unsigned long rip) void vmemmap_remap_free(unsigned long start, unsigned long end, unsigned long reuse); +int vmemmap_remap_alloc(unsigned long start, unsigned long end, + unsigned long reuse, gfp_t gfp_mask); void *sparse_buffer_alloc(unsigned long size); struct page * __populate_section_memmap(unsigned long pfn, diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 4cfca27c6d32..5518283aa667 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1397,16 +1397,26 @@ static void __free_huge_page(struct page *page) h->resv_huge_pages++; if (HPageTemporary(page)) { - list_del(&page->lru); ClearHPageTemporary(page); + + if (alloc_huge_page_vmemmap(h, page, GFP_ATOMIC)) { + h->surplus_huge_pages++; + h->surplus_huge_pages_node[nid]++; + goto enqueue; + } + list_del(&page->lru); update_and_free_page(h, page); } else if (h->surplus_huge_pages_node[nid]) { + if (alloc_huge_page_vmemmap(h, page, GFP_ATOMIC)) + goto enqueue; + /* remove the page from active list */ list_del(&page->lru); update_and_free_page(h, page); h->surplus_huge_pages--; h->surplus_huge_pages_node[nid]--; } else { +enqueue: arch_clear_hugepage_flags(page); enqueue_huge_page(h, page); } @@ -1693,6 +1703,10 @@ static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, struct page *page = list_entry(h->hugepage_freelists[node].next, struct page, lru); + + if (alloc_huge_page_vmemmap(h, page, GFP_ATOMIC)) + break; + list_del(&page->lru); h->free_huge_pages--; h->free_huge_pages_node[node]--; @@ -1760,6 +1774,9 @@ int dissolve_free_huge_page(struct page *page) goto retry; } + if (alloc_huge_page_vmemmap(h, head, GFP_ATOMIC)) + goto out; + /* * Move PageHWPoison flag from head page to the raw error page, * which makes any subpages rather than the error page reusable. diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index ddd872ab6180..0bd6b8d7282d 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -169,6 +169,8 @@ * (last) level. So this type of HugeTLB page can be optimized only when its * size of the struct page structs is greater than 2 pages. */ +#define pr_fmt(fmt) "HugeTLB: " fmt + #include "hugetlb_vmemmap.h" /* @@ -198,6 +200,34 @@ static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT; } +int alloc_huge_page_vmemmap(struct hstate *h, struct page *head, gfp_t gfp_mask) +{ + int ret; + unsigned long vmemmap_addr = (unsigned long)head; + unsigned long vmemmap_end, vmemmap_reuse; + + if (!free_vmemmap_pages_per_hpage(h)) + return 0; + + vmemmap_addr += RESERVE_VMEMMAP_SIZE; + vmemmap_end = vmemmap_addr + free_vmemmap_pages_size_per_hpage(h); + vmemmap_reuse = vmemmap_addr - PAGE_SIZE; + + /* + * The pages which the vmemmap virtual address range [@vmemmap_addr, + * @vmemmap_end) are mapped to are freed to the buddy allocator, and + * the range is mapped to the page which @vmemmap_reuse is mapped to. + * When a HugeTLB page is freed to the buddy allocator, previously + * discarded vmemmap pages must be allocated and remapping. + */ + ret = vmemmap_remap_alloc(vmemmap_addr, vmemmap_end, vmemmap_reuse, + gfp_mask | __GFP_NOWARN | __GFP_THISNODE); + if (ret == -ENOMEM) + pr_info("cannot alloc vmemmap pages\n"); + + return ret; +} + void free_huge_page_vmemmap(struct hstate *h, struct page *head) { unsigned long vmemmap_addr = (unsigned long)head; diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h index 6923f03534d5..6f89a9eed02c 100644 --- a/mm/hugetlb_vmemmap.h +++ b/mm/hugetlb_vmemmap.h @@ -11,8 +11,16 @@ #include #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP +int alloc_huge_page_vmemmap(struct hstate *h, struct page *head, + gfp_t gfp_mask); void free_huge_page_vmemmap(struct hstate *h, struct page *head); #else +static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head, + gfp_t gfp_mask) +{ + return 0; +} + static inline void free_huge_page_vmemmap(struct hstate *h, struct page *head) { } diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 50c1dc00b686..277eb43aebd5 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -40,7 +40,8 @@ * @remap_pte: called for each non-empty PTE (lowest-level) entry. * @reuse_page: the page which is reused for the tail vmemmap pages. * @reuse_addr: the virtual address of the @reuse_page page. - * @vmemmap_pages: the list head of the vmemmap pages that can be freed. + * @vmemmap_pages: the list head of the vmemmap pages that can be freed + * or is mapped from. */ struct vmemmap_remap_walk { void (*remap_pte)(pte_t *pte, unsigned long addr, @@ -237,6 +238,78 @@ void vmemmap_remap_free(unsigned long start, unsigned long end, free_vmemmap_page_list(&vmemmap_pages); } +static void vmemmap_restore_pte(pte_t *pte, unsigned long addr, + struct vmemmap_remap_walk *walk) +{ + pgprot_t pgprot = PAGE_KERNEL; + struct page *page; + void *to; + + BUG_ON(pte_page(*pte) != walk->reuse_page); + + page = list_first_entry(walk->vmemmap_pages, struct page, lru); + list_del(&page->lru); + to = page_to_virt(page); + copy_page(to, (void *)walk->reuse_addr); + + set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot)); +} + +static int alloc_vmemmap_page_list(unsigned long start, unsigned long end, + gfp_t gfp_mask, struct list_head *list) +{ + unsigned long addr; + int nid = page_to_nid((const void *)start); + struct page *page, *next; + + for (addr = start; addr < end; addr += PAGE_SIZE) { + page = alloc_pages_node(nid, gfp_mask, 0); + if (!page) + goto out; + list_add_tail(&page->lru, list); + } + + return 0; +out: + list_for_each_entry_safe(page, next, list, lru) + __free_pages(page, 0); + return -ENOMEM; +} + +/** + * vmemmap_remap_alloc - remap the vmemmap virtual address range [@start, end) + * to the page which is from the @vmemmap_pages + * respectively. + * @start: start address of the vmemmap virtual address range that we want + * to remap. + * @end: end address of the vmemmap virtual address range that we want to + * remap. + * @reuse: reuse address. + * @gpf_mask: GFP flag for allocating vmemmap pages. + */ +int vmemmap_remap_alloc(unsigned long start, unsigned long end, + unsigned long reuse, gfp_t gfp_mask) +{ + LIST_HEAD(vmemmap_pages); + struct vmemmap_remap_walk walk = { + .remap_pte = vmemmap_restore_pte, + .reuse_addr = reuse, + .vmemmap_pages = &vmemmap_pages, + }; + + /* See the comment in the vmemmap_remap_free(). */ + BUG_ON(start - reuse != PAGE_SIZE); + + might_sleep_if(gfpflags_allow_blocking(gfp_mask)); + + if (alloc_vmemmap_page_list(start, end, gfp_mask, &vmemmap_pages)) + return -ENOMEM; + + vmemmap_remap_range(reuse, end, &walk); + + return 0; +} + /* * Allocate a block of memory to be used to back the virtual memory map * or to back the page tables that are used to create the mapping. 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We disables PMD mapping of vmemmap pages for x86-64 arch when this feature is enabled. Because vmemmap_remap_free() depends on vmemmap being base page mapped. Signed-off-by: Muchun Song Reviewed-by: Oscar Salvador Reviewed-by: Barry Song Reviewed-by: Miaohe Lin --- Documentation/admin-guide/kernel-parameters.txt | 14 ++++++++++++++ Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ arch/x86/mm/init_64.c | 8 ++++++-- include/linux/hugetlb.h | 19 +++++++++++++++++++ mm/hugetlb_vmemmap.c | 22 ++++++++++++++++++++++ 5 files changed, 64 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 5adf1e57e932..7db2591f3ad3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1577,6 +1577,20 @@ Documentation/admin-guide/mm/hugetlbpage.rst. Format: size[KMG] + hugetlb_free_vmemmap= + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, + this controls freeing unused vmemmap pages associated + with each HugeTLB page. When this option is enabled, + we disable PMD/huge page mapping of vmemmap pages which + increase page table pages. So if a user/sysadmin only + uses a small number of HugeTLB pages (as a percentage + of system memory), they could end up using more memory + with hugetlb_free_vmemmap on as opposed to off. + Format: { on | off (default) } + + on: enable the feature + off: disable the feature + hung_task_panic= [KNL] Should the hung task detector generate panics. Format: 0 | 1 diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst index f7b1c7462991..3a23c2377acc 100644 --- a/Documentation/admin-guide/mm/hugetlbpage.rst +++ b/Documentation/admin-guide/mm/hugetlbpage.rst @@ -145,6 +145,9 @@ default_hugepagesz will all result in 256 2M huge pages being allocated. Valid default huge page size is architecture dependent. +hugetlb_free_vmemmap + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing + unused vmemmap pages associated with each HugeTLB page. When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` indicates the current number of pre-allocated huge pages of the default size. diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 0435bee2e172..39f88c5faadc 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include @@ -1557,7 +1558,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, { int err; - if (end - start < PAGES_PER_SECTION * sizeof(struct page)) + if ((is_hugetlb_free_vmemmap_enabled() && !altmap) || + end - start < PAGES_PER_SECTION * sizeof(struct page)) err = vmemmap_populate_basepages(start, end, node, NULL); else if (boot_cpu_has(X86_FEATURE_PSE)) err = vmemmap_populate_hugepages(start, end, node, altmap); @@ -1585,6 +1587,8 @@ void register_page_bootmem_memmap(unsigned long section_nr, pmd_t *pmd; unsigned int nr_pmd_pages; struct page *page; + bool base_mapping = !boot_cpu_has(X86_FEATURE_PSE) || + is_hugetlb_free_vmemmap_enabled(); for (; addr < end; addr = next) { pte_t *pte = NULL; @@ -1610,7 +1614,7 @@ void register_page_bootmem_memmap(unsigned long section_nr, } get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); - if (!boot_cpu_has(X86_FEATURE_PSE)) { + if (base_mapping) { next = (addr + PAGE_SIZE) & PAGE_MASK; pmd = pmd_offset(pud, addr); if (pmd_none(*pmd)) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 37fd248ce271..ad249e56ac49 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -854,6 +854,20 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, void set_page_huge_active(struct page *page); +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP +extern bool hugetlb_free_vmemmap_enabled; + +static inline bool is_hugetlb_free_vmemmap_enabled(void) +{ + return hugetlb_free_vmemmap_enabled; +} +#else +static inline bool is_hugetlb_free_vmemmap_enabled(void) +{ + return false; +} +#endif + #else /* CONFIG_HUGETLB_PAGE */ struct hstate {}; @@ -1007,6 +1021,11 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr pte_t *ptep, pte_t pte, unsigned long sz) { } + +static inline bool is_hugetlb_free_vmemmap_enabled(void) +{ + return false; +} #endif /* CONFIG_HUGETLB_PAGE */ static inline spinlock_t *huge_pte_lock(struct hstate *h, diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 0bd6b8d7282d..224a3cb69bf9 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -183,6 +183,28 @@ #define RESERVE_VMEMMAP_NR 2U #define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT) +bool hugetlb_free_vmemmap_enabled; + +static int __init early_hugetlb_free_vmemmap_param(char *buf) +{ + /* We cannot optimize if a "struct page" crosses page boundaries. */ + if ((!is_power_of_2(sizeof(struct page)))) { + pr_warn("cannot free vmemmap pages because \"struct page\" crosses page boundaries\n"); + return 0; + } + + if (!buf) + return -EINVAL; + + if (!strcmp(buf, "on")) + hugetlb_free_vmemmap_enabled = true; + else if (strcmp(buf, "off")) + return -EINVAL; + + return 0; +} +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); + /* * How many vmemmap pages associated with a HugeTLB page that can be freed * to the buddy allocator. From patchwork Thu Feb 4 03:50:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12066263 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 BC0BCC433E6 for ; Thu, 4 Feb 2021 03:58:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7477D64F60 for ; Thu, 4 Feb 2021 03:58:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232822AbhBDD6L (ORCPT ); Wed, 3 Feb 2021 22:58:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232026AbhBDDzy (ORCPT ); Wed, 3 Feb 2021 22:55:54 -0500 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B8E5C0617AA for ; Wed, 3 Feb 2021 19:55:05 -0800 (PST) Received: by mail-pj1-x1029.google.com with SMTP id fa16so495863pjb.1 for ; Wed, 03 Feb 2021 19:55:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=61XssS9hC3yvdXbWzdJhtTR8Yjia1vJaQF8aPfeYJmw=; b=hEsjQq399BYLQaa4G3mACRWtXR09Qe1HRCTJcok9uAmiEzX414JVvCHs4NvNaGS96O HYnGMvn5VX804tR3PJ9YNjyaZ+bZexbWkByhPRPmed35G2BIXgaXQq99yrweVBtjvSGr r+nQUBh5KGyMpyDgBZSLQmNihvxZ9hISeoCpoubaIHyqLNFP1qm99WG9M+6/+VCojM/W G9mltVuVoTpE5M1CIwZmFWvpvMgblU8pIqYKDgqJ4L05GXbH3k2DMQ6ZVBcreMNLvUhp 3IUL3IMl+wmA1GJgpIAdDRtfs4SFf8ss3k46nNAT4thHWwYVTxWwFNxv+fHvTGs2rHZM j+aQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=61XssS9hC3yvdXbWzdJhtTR8Yjia1vJaQF8aPfeYJmw=; b=XY1ZqWfl3st0b2RqMVkL+lLWiz/whOzvIg+o3SHFW6jKT5QkBvWqv0xJyQRwBQuwBi hK0f68CkiyYcyL7ddTMDdc0liNKi++dxC3cUmhQ4qwnaMhQVVDaUZ+WfD46dzD672+LM 3NYgexhuITk+XlKJmyXriVfuwhYIFj3qxNoVBVyXSJg3p0kHIn9hwatLhT55GdixQydh LPFGWRprsYF+Pd671WIc8ExGdPmjn2VdovMux6GvAf6UsF8QEmEhB2IRuDlU5lQzRI6l mqK89V+QQnjpx4fyPdIcuLBWS+MN2I9DXBymkKQ2xqRE4pRagq+IQ8R3kPWpzxYVGUBG M+Xw== X-Gm-Message-State: AOAM5329XpMQLDsPQ/ojv8D+qizJTVdgL3XZ7d3G2XGymFMdueEpU6cA bk0gmpNqlxJv0AWQVa2g4sKyfQ== X-Google-Smtp-Source: ABdhPJymEyO5jCkZDSiQkPoZ425GLmAnOcns72vBeQg76oX3E/2kTSUpaVxq6nyo8yaTnx2fBBny0w== X-Received: by 2002:a17:90a:ab17:: with SMTP id m23mr6228475pjq.0.1612410905026; Wed, 03 Feb 2021 19:55:05 -0800 (PST) Received: from localhost.localdomain ([139.177.225.239]) by smtp.gmail.com with ESMTPSA id 9sm3747466pfy.110.2021.02.03.19.54.53 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Feb 2021 19:55:04 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v14 6/8] mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate Date: Thu, 4 Feb 2021 11:50:41 +0800 Message-Id: <20210204035043.36609-7-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210204035043.36609-1-songmuchun@bytedance.com> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org All the infrastructure is ready, so we introduce nr_free_vmemmap_pages field in the hstate to indicate how many vmemmap pages associated with a HugeTLB page that can be freed to buddy allocator. And initialize it in the hugetlb_vmemmap_init(). This patch is actual enablement of the feature. Signed-off-by: Muchun Song Acked-by: Mike Kravetz Reviewed-by: Oscar Salvador Reviewed-by: Miaohe Lin --- include/linux/hugetlb.h | 3 +++ mm/hugetlb.c | 1 + mm/hugetlb_vmemmap.c | 30 ++++++++++++++++++++++++++---- mm/hugetlb_vmemmap.h | 5 +++++ 4 files changed, 35 insertions(+), 4 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index ad249e56ac49..775aea53669a 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -560,6 +560,9 @@ struct hstate { unsigned int nr_huge_pages_node[MAX_NUMNODES]; unsigned int free_huge_pages_node[MAX_NUMNODES]; unsigned int surplus_huge_pages_node[MAX_NUMNODES]; +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP + unsigned int nr_free_vmemmap_pages; +#endif #ifdef CONFIG_CGROUP_HUGETLB /* cgroup control files */ struct cftype cgroup_files_dfl[7]; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5518283aa667..04dde2b71f3e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3220,6 +3220,7 @@ void __init hugetlb_add_hstate(unsigned int order) h->next_nid_to_free = first_memory_node; snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", huge_page_size(h)/1024); + hugetlb_vmemmap_init(h); parsed_hstate = h; } diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 224a3cb69bf9..36ebd677e606 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -208,13 +208,10 @@ early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); /* * How many vmemmap pages associated with a HugeTLB page that can be freed * to the buddy allocator. - * - * Todo: Returns zero for now, which means the feature is disabled. We will - * enable it once all the infrastructure is there. */ static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) { - return 0; + return h->nr_free_vmemmap_pages; } static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h) @@ -269,3 +266,28 @@ void free_huge_page_vmemmap(struct hstate *h, struct page *head) */ vmemmap_remap_free(vmemmap_addr, vmemmap_end, vmemmap_reuse); } + +void __init hugetlb_vmemmap_init(struct hstate *h) +{ + unsigned int nr_pages = pages_per_huge_page(h); + unsigned int vmemmap_pages; + + if (!hugetlb_free_vmemmap_enabled) + return; + + vmemmap_pages = (nr_pages * sizeof(struct page)) >> PAGE_SHIFT; + /* + * The head page and the first tail page are not to be freed to buddy + * allocator, the other pages will map to the first tail page, so they + * can be freed. + * + * Could RESERVE_VMEMMAP_NR be greater than @vmemmap_pages? It is true + * on some architectures (e.g. aarch64). See Documentation/arm64/ + * hugetlbpage.rst for more details. + */ + if (likely(vmemmap_pages > RESERVE_VMEMMAP_NR)) + h->nr_free_vmemmap_pages = vmemmap_pages - RESERVE_VMEMMAP_NR; + + pr_info("can free %d vmemmap pages for %s\n", h->nr_free_vmemmap_pages, + h->name); +} diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h index 6f89a9eed02c..02a21604ef1d 100644 --- a/mm/hugetlb_vmemmap.h +++ b/mm/hugetlb_vmemmap.h @@ -14,6 +14,7 @@ int alloc_huge_page_vmemmap(struct hstate *h, struct page *head, gfp_t gfp_mask); void free_huge_page_vmemmap(struct hstate *h, struct page *head); +void hugetlb_vmemmap_init(struct hstate *h); #else static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head, gfp_t gfp_mask) @@ -24,5 +25,9 @@ static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head, static inline void free_huge_page_vmemmap(struct hstate *h, struct page *head) { } + +static inline void hugetlb_vmemmap_init(struct hstate *h) +{ +} #endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */ #endif /* _LINUX_HUGETLB_VMEMMAP_H */ From patchwork Thu Feb 4 03:50:42 2021 Content-Type: text/plain; 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Wed, 03 Feb 2021 19:55:18 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v14 7/8] mm: hugetlb: gather discrete indexes of tail page Date: Thu, 4 Feb 2021 11:50:42 +0800 Message-Id: <20210204035043.36609-8-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210204035043.36609-1-songmuchun@bytedance.com> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org For HugeTLB page, there are more metadata to save in the struct page. But the head struct page cannot meet our needs, so we have to abuse other tail struct page to store the metadata. In order to avoid conflicts caused by subsequent use of more tail struct pages, we can gather these discrete indexes of tail struct page. In this case, it will be easier to add a new tail page index later. There are only (RESERVE_VMEMMAP_SIZE / sizeof(struct page)) struct page structs that can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so add a BUILD_BUG_ON to catch invalid usage of the tail struct page. Signed-off-by: Muchun Song Reviewed-by: Oscar Salvador Reviewed-by: Miaohe Lin --- include/linux/hugetlb.h | 20 ++++++++++++++++++-- include/linux/hugetlb_cgroup.h | 19 +++++++++++-------- mm/hugetlb_vmemmap.c | 8 ++++++++ 3 files changed, 37 insertions(+), 10 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 775aea53669a..822ab2f5542a 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -28,6 +28,22 @@ typedef struct { unsigned long pd; } hugepd_t; #include #include +/* + * For HugeTLB page, there are more metadata to save in the struct page. But + * the head struct page cannot meet our needs, so we have to abuse other tail + * struct page to store the metadata. In order to avoid conflicts caused by + * subsequent use of more tail struct pages, we gather these discrete indexes + * of tail struct page here. + */ +enum { + SUBPAGE_INDEX_SUBPOOL = 1, /* reuse page->private */ +#ifdef CONFIG_CGROUP_HUGETLB + SUBPAGE_INDEX_CGROUP, /* reuse page->private */ + SUBPAGE_INDEX_CGROUP_RSVD, /* reuse page->private */ +#endif + NR_USED_SUBPAGE, +}; + struct hugepage_subpool { spinlock_t lock; long count; @@ -607,13 +623,13 @@ extern unsigned int default_hstate_idx; */ static inline struct hugepage_subpool *hugetlb_page_subpool(struct page *hpage) { - return (struct hugepage_subpool *)(hpage+1)->private; + return (void *)page_private(hpage + SUBPAGE_INDEX_SUBPOOL); } static inline void hugetlb_set_page_subpool(struct page *hpage, struct hugepage_subpool *subpool) { - set_page_private(hpage+1, (unsigned long)subpool); + set_page_private(hpage + SUBPAGE_INDEX_SUBPOOL, (unsigned long)subpool); } static inline struct hstate *hstate_file(struct file *f) diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h index 2ad6e92f124a..c0cae6a704f2 100644 --- a/include/linux/hugetlb_cgroup.h +++ b/include/linux/hugetlb_cgroup.h @@ -21,15 +21,16 @@ struct hugetlb_cgroup; struct resv_map; struct file_region; +#ifdef CONFIG_CGROUP_HUGETLB /* * Minimum page order trackable by hugetlb cgroup. * At least 4 pages are necessary for all the tracking information. - * The second tail page (hpage[2]) is the fault usage cgroup. - * The third tail page (hpage[3]) is the reservation usage cgroup. + * The second tail page (hpage[SUBPAGE_INDEX_CGROUP]) is the fault + * usage cgroup. The third tail page (hpage[SUBPAGE_INDEX_CGROUP_RSVD]) + * is the reservation usage cgroup. */ -#define HUGETLB_CGROUP_MIN_ORDER 2 +#define HUGETLB_CGROUP_MIN_ORDER order_base_2(NR_USED_SUBPAGE) -#ifdef CONFIG_CGROUP_HUGETLB enum hugetlb_memory_event { HUGETLB_MAX, HUGETLB_NR_MEMORY_EVENTS, @@ -66,9 +67,9 @@ __hugetlb_cgroup_from_page(struct page *page, bool rsvd) if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER) return NULL; if (rsvd) - return (struct hugetlb_cgroup *)page[3].private; + return (void *)page_private(page + SUBPAGE_INDEX_CGROUP_RSVD); else - return (struct hugetlb_cgroup *)page[2].private; + return (void *)page_private(page + SUBPAGE_INDEX_CGROUP); } static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) @@ -90,9 +91,11 @@ static inline int __set_hugetlb_cgroup(struct page *page, if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER) return -1; if (rsvd) - page[3].private = (unsigned long)h_cg; + set_page_private(page + SUBPAGE_INDEX_CGROUP_RSVD, + (unsigned long)h_cg); else - page[2].private = (unsigned long)h_cg; + set_page_private(page + SUBPAGE_INDEX_CGROUP, + (unsigned long)h_cg); return 0; } diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 36ebd677e606..8efad9978821 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -272,6 +272,14 @@ void __init hugetlb_vmemmap_init(struct hstate *h) unsigned int nr_pages = pages_per_huge_page(h); unsigned int vmemmap_pages; + /* + * There are only (RESERVE_VMEMMAP_SIZE / sizeof(struct page)) struct + * page structs that can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, + * so add a BUILD_BUG_ON to catch invalid usage of the tail struct page. + */ + BUILD_BUG_ON(NR_USED_SUBPAGE >= + RESERVE_VMEMMAP_SIZE / sizeof(struct page)); + if (!hugetlb_free_vmemmap_enabled) return; From patchwork Thu Feb 4 03:50:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12066261 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 9C03EC433E0 for ; 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Wed, 03 Feb 2021 19:55:31 -0800 (PST) Received: from localhost.localdomain ([139.177.225.239]) by smtp.gmail.com with ESMTPSA id 9sm3747466pfy.110.2021.02.03.19.55.19 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Feb 2021 19:55:31 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v14 8/8] mm: hugetlb: optimize the code with the help of the compiler Date: Thu, 4 Feb 2021 11:50:43 +0800 Message-Id: <20210204035043.36609-9-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210204035043.36609-1-songmuchun@bytedance.com> References: <20210204035043.36609-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org We cannot optimize if a "struct page" crosses page boundaries. If it is true, we can optimize the code with the help of a compiler. When free_vmemmap_pages_per_hpage() returns zero, most functions are optimized by the compiler. Signed-off-by: Muchun Song Reviewed-by: Miaohe Lin Reviewed-by: Oscar Salvador --- include/linux/hugetlb.h | 3 ++- mm/hugetlb_vmemmap.c | 13 +++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 822ab2f5542a..7bfb06e16298 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -878,7 +878,8 @@ extern bool hugetlb_free_vmemmap_enabled; static inline bool is_hugetlb_free_vmemmap_enabled(void) { - return hugetlb_free_vmemmap_enabled; + return hugetlb_free_vmemmap_enabled && + is_power_of_2(sizeof(struct page)); } #else static inline bool is_hugetlb_free_vmemmap_enabled(void) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 8efad9978821..068d0e0cebc8 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -211,6 +211,12 @@ early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); */ static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) { + /* + * This check aims to let the compiler help us optimize the code as + * much as possible. + */ + if (!is_power_of_2(sizeof(struct page))) + return 0; return h->nr_free_vmemmap_pages; } @@ -280,6 +286,13 @@ void __init hugetlb_vmemmap_init(struct hstate *h) BUILD_BUG_ON(NR_USED_SUBPAGE >= RESERVE_VMEMMAP_SIZE / sizeof(struct page)); + /* + * The compiler can help us to optimize this function to null + * when the size of the struct page is not power of 2. + */ + if (!is_power_of_2(sizeof(struct page))) + return; + if (!hugetlb_free_vmemmap_enabled) return;