From patchwork Wed Jan 6 14:19:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12001803 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 63FDEC4332B for ; Wed, 6 Jan 2021 14:23:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33E6723100 for ; Wed, 6 Jan 2021 14:23:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727245AbhAFOW6 (ORCPT ); Wed, 6 Jan 2021 09:22:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727205AbhAFOW5 (ORCPT ); Wed, 6 Jan 2021 09:22:57 -0500 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A2E3C061367 for ; Wed, 6 Jan 2021 06:22:17 -0800 (PST) Received: by mail-pg1-x534.google.com with SMTP id z21so2327263pgj.4 for ; Wed, 06 Jan 2021 06:22:17 -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=0r+JCD4Y++UkuwDhT+3Um93OT5s28ZmvypPmtNNw098=; b=0oF8sPkGeGWx9ukIJVPBb+SZMoQ49Fevj/R/GyvaHfEsNs1lOrExzKY0hvyyWCD0NS S9zsFrSJBzSmn9JrSCEm2aLAfGsO7LPegVqWpOUkCDWx9mKZrbpUDR5uM476sUInZEnf f/q1zs/AzKNYPeGrTILtVZWuVbJPf8iy/hFHH8ZuwcNpWKbiaRBwbPYwLxIRv5oaw9vU LEiRj6TkS66B47ZgLPhgk+7DDxHNq2hARNEMWzeKRPmwVa6C0GoHu7Q9Fx+DMiTmJUjo zqiGiiAachQNakQIvI7KnBAjNlgCTDE3fccwU5LbmCleeg7Wk+3BAvs6LFXlPJZPxZB8 fMpg== 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=0r+JCD4Y++UkuwDhT+3Um93OT5s28ZmvypPmtNNw098=; b=dbdLkJoxCRjHIYPvSjphR6z8LD9qEiPUBLl0siTShFXun1PitUwZNfp5a9MHv5Ki37 932yb9QhlpeyJLx955oG9FlYo14AYoJKAvDq2Aye9nkxNrBawgpx3VZL7QrqoaGAQpeY 6t5j8RZm9FFCEXdAPCJHF55ZgxRZCR/LMBasYnzTK1WY/3aROnQYDralvDCauv+gJ2pJ IIwHKhKJMDsckuZwRbU+dx3whEYTjIrJvpUbempWtkjVt1PzCcncBBXhDV/goFFZ0JI1 +DF+/MsKKXMN6XOFVbOSgpWcrmpmh5/8SPgzlZ7n70tr6WzxqL+dqc2/tzISKidG27LE aahQ== X-Gm-Message-State: AOAM531Gd9WjuzUhCYAr8zdoq5KyXulr65mnA3eTlvakXvveEwGj0AAJ 0cEEdSNQ9BUbPORebt//H3l+3w== X-Google-Smtp-Source: ABdhPJzQOhLogQTjbj6ySAdXlr5segTb7DwvuqxANst0DnqCc84VLCeKgWpDANHab75PlrynQnZySg== X-Received: by 2002:a63:5b08:: with SMTP id p8mr4814053pgb.108.1609942936640; Wed, 06 Jan 2021 06:22:16 -0800 (PST) Received: from localhost.bytedance.net ([139.177.225.232]) by smtp.gmail.com with ESMTPSA id a29sm2831730pfr.73.2021.01.06.06.22.05 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 06 Jan 2021 06:22:16 -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 v12 12/13] mm/hugetlb: Gather discrete indexes of tail page Date: Wed, 6 Jan 2021 22:19:30 +0800 Message-Id: <20210106141931.73931-13-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210106141931.73931-1-songmuchun@bytedance.com> References: <20210106141931.73931-1-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 --- include/linux/hugetlb.h | 14 ++++++++++++++ include/linux/hugetlb_cgroup.h | 15 +++++++++------ mm/hugetlb.c | 25 ++++++++++++------------- mm/hugetlb_vmemmap.c | 8 ++++++++ 4 files changed, 43 insertions(+), 19 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 66d82ae7b712..05fd2db09b78 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -28,6 +28,20 @@ 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 */ + SUBPAGE_INDEX_INFLIGHT, /* 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 0e14fad63823..fdabc1d0ef98 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1346,17 +1346,17 @@ static inline void flush_hpage_update_work(struct hstate *h) #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP static inline bool PageHugeInflight(struct page *head) { - return page_private(head + 5) == -1UL; + return page_private(head + SUBPAGE_INDEX_INFLIGHT) == -1UL; } static inline void SetPageHugeInflight(struct page *head) { - set_page_private(head + 5, -1UL); + set_page_private(head + SUBPAGE_INDEX_INFLIGHT, -1UL); } static inline void ClearPageHugeInflight(struct page *head) { - set_page_private(head + 5, 0); + set_page_private(head + SUBPAGE_INDEX_INFLIGHT, 0); } #else static inline bool PageHugeInflight(struct page *head) @@ -1404,7 +1404,7 @@ 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, @@ -1423,7 +1423,7 @@ 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, @@ -1433,7 +1433,6 @@ static inline void hwpoison_subpage_set(struct hstate *h, struct page *head, ClearPageHWPoison(head); } } - #else static inline void hwpoison_subpage_deliver(struct hstate *h, struct page *head) { @@ -1514,20 +1513,20 @@ 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]); } /* @@ -1539,17 +1538,17 @@ 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) @@ -3374,7 +3373,7 @@ void __init hugetlb_add_hstate(unsigned int order) return; } BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); - BUG_ON(order == 0); + BUG_ON((1U << order) < NR_USED_SUBPAGE); h = &hstates[hugetlb_max_hstate++]; h->order = order; h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 7dcb4aa1e512..6b8f7bb2273e 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -242,6 +242,14 @@ 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;