From patchwork Sun Dec 13 15:45:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 11970839 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,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 21475C4361B for ; Sun, 13 Dec 2020 15:49:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8A7F2313B for ; Sun, 13 Dec 2020 15:49:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437333AbgLMPsv (ORCPT ); Sun, 13 Dec 2020 10:48:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437304AbgLMPsp (ORCPT ); Sun, 13 Dec 2020 10:48:45 -0500 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71EC8C061793 for ; Sun, 13 Dec 2020 07:48:05 -0800 (PST) Received: by mail-pj1-x1043.google.com with SMTP id f14so4868617pju.4 for ; Sun, 13 Dec 2020 07:48:05 -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=8NPGizKXhIw6LYHXB/g9S8tO1PI1jnab/kHwdu+D4Ug=; b=oPhLptY/qqtVKcudr08x3sHl/beeopjU2TvjrXHJdbdVPPdS0MzXzYtLXXVwG0Kq9T LBT6BWP2ta14GXxYp9tksWuJeAS6qn8SpJY6r47m4sdbVKSIoNgUnqC28+KRfhvgKzEh rHf6XfhSkWrc68sLAIaVZLFfxWgZgB72Nj/z8hfBYNIXbuuIa+S/Q/pvITtnuZtVnEDK TFUj9PXtBxk4BkbUr2lzrE+//C5cLsozVE4abh8MKeo0enW/Mn00E07+Y9fL+wNaGikY JeGvaAfrOQgZ77NQUeCvXlv8TZTtitHBy8BVJVTBoWOQx2l8K82DhTAZbOUksv7sGT0i 57CQ== 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=8NPGizKXhIw6LYHXB/g9S8tO1PI1jnab/kHwdu+D4Ug=; b=ARspN9617ddH5qN5njz7afVJJHcgzgI7cWsikC04LhvHuLEv5oFypI+5hXxEWPo9z1 sHLGl1wuG60fudjwuG9Ti4EiOCDINHwPpFHp2mklSViHZkZ/cS/sSXt9Ek6x80860hrd QF3ft43DzcHZe20WKyiaC4T7uJaPjLC6ofivWXdGUTINs7oO4lFWW9JkU6h/Zb/zYqGA ayzBndyIvQFzxJisMTqrHgIDZdPe7Ee21q7wD5oZmmUkTCTEwKs7v7gHNcZiX5VTpgRx dkoCSdwDcolJVb6VKaINaPLCxUR8+jqLVq7uHUrcNkv0U/u/UEqv10K1GcZW1KN16hBK IhYA== X-Gm-Message-State: AOAM533eb2YokmDZks4M/GEzcPN7D+x97CgfDqgPhkFfGGucwXWLIpMW xP58/fgB+pRYmVSLxlZX3h9coQ== X-Google-Smtp-Source: ABdhPJzpr/Z/RxuagpBkxf5dniRoM/fCaPYTeqJPB/w+ZQSOkCMu4OPhrK8dBKr4Mu4cgwEFvFE4oA== X-Received: by 2002:a17:90b:4a81:: with SMTP id lp1mr22041651pjb.55.1607874485011; Sun, 13 Dec 2020 07:48:05 -0800 (PST) Received: from localhost.bytedance.net ([103.136.221.66]) by smtp.gmail.com with ESMTPSA id e24sm13113753pjt.16.2020.12.13.07.47.55 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 13 Dec 2020 07:48:04 -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 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 v9 10/11] mm/hugetlb: Gather discrete indexes of tail page Date: Sun, 13 Dec 2020 23:45:33 +0800 Message-Id: <20201213154534.54826-11-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20201213154534.54826-1-songmuchun@bytedance.com> References: <20201213154534.54826-1-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 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 --- include/linux/hugetlb.h | 13 +++++++++++++ include/linux/hugetlb_cgroup.h | 15 +++++++++------ mm/hugetlb.c | 16 ++++++++-------- mm/hugetlb_vmemmap.c | 8 ++++++++ 4 files changed, 38 insertions(+), 14 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 66d82ae7b712..7295f6b3d55e 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -28,6 +28,19 @@ typedef struct { unsigned long pd; } hugepd_t; #include #include +enum { + SUBPAGE_INDEX_ACTIVE = 1, /* reuse page flags of PG_private */ + SUBPAGE_INDEX_TEMPORARY, /* reuse page->mapping */ +#ifdef CONFIG_CGROUP_HUGETLB + SUBPAGE_INDEX_CGROUP = SUBPAGE_INDEX_TEMPORARY,/* reuse page->private */ + SUBPAGE_INDEX_CGROUP_RSVD, /* reuse page->private */ +#endif +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP + SUBPAGE_INDEX_HWPOISON, /* reuse page->private */ +#endif + NR_USED_SUBPAGE, +}; + struct hugepage_subpool { spinlock_t lock; long count; diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h index 2ad6e92f124a..3d3c1c49efe4 100644 --- a/include/linux/hugetlb_cgroup.h +++ b/include/linux/hugetlb_cgroup.h @@ -24,8 +24,9 @@ struct file_region; /* * 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 @@ -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.c b/mm/hugetlb.c index 2b45235a70e9..0e8f13184de0 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1360,7 +1360,7 @@ static inline void hwpoison_subpage_deliver(struct hstate *h, struct page *head) if (!PageHWPoison(head) || !free_vmemmap_pages_per_hpage(h)) return; - page = head + page_private(head + 4); + page = head + page_private(head + SUBPAGE_INDEX_HWPOISON); /* * Move PageHWPoison flag from head page to the raw error page, @@ -1379,7 +1379,7 @@ static inline void hwpoison_subpage_set(struct hstate *h, struct page *head, return; if (free_vmemmap_pages_per_hpage(h)) { - set_page_private(head + 4, page - head); + set_page_private(head + SUBPAGE_INDEX_HWPOISON, page - head); } else if (page != head) { /* * Move PageHWPoison flag from head page to the raw error page, @@ -1456,20 +1456,20 @@ struct hstate *size_to_hstate(unsigned long size) bool page_huge_active(struct page *page) { VM_BUG_ON_PAGE(!PageHuge(page), page); - return PageHead(page) && PagePrivate(&page[1]); + return PageHead(page) && PagePrivate(&page[SUBPAGE_INDEX_ACTIVE]); } /* never called for tail page */ static void set_page_huge_active(struct page *page) { VM_BUG_ON_PAGE(!PageHeadHuge(page), page); - SetPagePrivate(&page[1]); + SetPagePrivate(&page[SUBPAGE_INDEX_ACTIVE]); } static void clear_page_huge_active(struct page *page) { VM_BUG_ON_PAGE(!PageHeadHuge(page), page); - ClearPagePrivate(&page[1]); + ClearPagePrivate(&page[SUBPAGE_INDEX_ACTIVE]); } /* @@ -1481,17 +1481,17 @@ static inline bool PageHugeTemporary(struct page *page) if (!PageHuge(page)) return false; - return (unsigned long)page[2].mapping == -1U; + return (unsigned long)page[SUBPAGE_INDEX_TEMPORARY].mapping == -1U; } static inline void SetPageHugeTemporary(struct page *page) { - page[2].mapping = (void *)-1U; + page[SUBPAGE_INDEX_TEMPORARY].mapping = (void *)-1U; } static inline void ClearPageHugeTemporary(struct page *page) { - page[2].mapping = NULL; + page[SUBPAGE_INDEX_TEMPORARY].mapping = NULL; } static void __free_huge_page(struct page *page) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index d3b4c39f67c0..bbcefd5fb7d1 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -232,6 +232,14 @@ 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 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;