From mboxrd@z Thu Jan 1 00:00:00 1970 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 1947AC2D0A3 for ; Mon, 26 Oct 2020 14:56:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D32BB2463C for ; Mon, 26 Oct 2020 14:56:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bytedance-com.20150623.gappssmtp.com header.i=@bytedance-com.20150623.gappssmtp.com header.b="bvJ+weNA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1782752AbgJZO4H (ORCPT ); Mon, 26 Oct 2020 10:56:07 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:51038 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1782744AbgJZO4E (ORCPT ); Mon, 26 Oct 2020 10:56:04 -0400 Received: by mail-pj1-f67.google.com with SMTP id p21so3380032pju.0 for ; Mon, 26 Oct 2020 07:56:03 -0700 (PDT) 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=L8s2C/dmr+hzCVncDgNolmMfa9FiU5L4x2d/qdrYiLM=; b=bvJ+weNAK62o0rqsgtIP0MF494iJCbOlFGfBQz4Tf9Be9dkFY02ErXnV2CkxwQaJov vqsGZ3GKTAsZrrZUC214OE93EHHrjfk5fqKqscbWBq8qOkomhTUcpOSIgSYpMpIijEaB ncDnCibpBpXWFQmxJirNhgJnLIs7QN6RcdYnunEWvzcZK4cgqUv3WM8JFgr3ShbPJq8x ABMaw8/KOGL5AgUEtVsuKaWbekW4Y49KPndxbHNz/cnMsvoCCrX2xsCB6PfP95KQn47H omQfSHbSMR7ihAMsvGPAb/mmD/Bdnjz95N+9qJYe2rbEafIlC8fOu8KgEDZ71ERVVQpC JloA== 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=L8s2C/dmr+hzCVncDgNolmMfa9FiU5L4x2d/qdrYiLM=; b=tr2ZDVgBtfeslq9Obu9lDGdBx4b1pZyVa4QPdMCwa82E60xUv1q2Pf0/tkivfXQ28f I2YsXnEkFeYAe/tn6KQOg0hMXnMY4EP0vimqWuY4x5/IraA4kUFudsP/HC3JPmKzMqsY Ec7RmRkQPVeq9jilD9MUbdtnUCM0XpPlJjV5XdCv38jWe5zPaVSjL88Q3Tv8wkfdRbPZ ITgPBQ8YmmJ4E19RS6qsJlnM+G1vu8DyBZQqYN4BnPMEcKlsfdFxU26u6194bi9MCJmi OXOtHezBZcB6WBZS4lsNilW0CgTTzuDGOSLWP9gWI/DIpcmS8N0xdd0/eXd4whZaoqdJ uGXg== X-Gm-Message-State: AOAM533juvVJqdaGLnVXlM5QNthnL0Ts4UwGlkskXK3Vm4WCvdK5wA4B LdtnxMWLbuhNRV0lu86CL0BUBA== X-Google-Smtp-Source: ABdhPJzligmAWidXFyuZPsN3hhtvBApJ3V4vmQY4KHzYlIoIpDOWARzwAlJv6luUtUdt32oM2nOhag== X-Received: by 2002:a17:90a:fa48:: with SMTP id dt8mr16879212pjb.108.1603724163086; Mon, 26 Oct 2020 07:56:03 -0700 (PDT) Received: from localhost.localdomain ([103.136.220.89]) by smtp.gmail.com with ESMTPSA id x123sm12042726pfb.212.2020.10.26.07.55.53 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Oct 2020 07:56:02 -0700 (PDT) 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 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 v2 18/19] mm/hugetlb: Gather discrete indexes of tail page Date: Mon, 26 Oct 2020 22:51:13 +0800 Message-Id: <20201026145114.59424-19-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20201026145114.59424-1-songmuchun@bytedance.com> References: <20201026145114.59424-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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. Signed-off-by: Muchun Song --- include/linux/hugetlb.h | 13 +++++++++++++ include/linux/hugetlb_cgroup.h | 15 +++++++++------ mm/hugetlb.c | 18 +++++++++--------- 3 files changed, 31 insertions(+), 15 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 3a45199cc5c1..6d377b6099f0 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 a526bcdb137b..029b00ed52ed 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1925,17 +1925,17 @@ static inline void flush_free_huge_page_work(void) static inline bool subpage_hwpoison(struct page *head, struct page *page) { - return page_private(head + 4) == page - head; + return page_private(head + SUBPAGE_INDEX_HWPOISON) == page - head; } static inline void set_subpage_hwpoison(struct page *head, struct page *page) { - set_page_private(head + 4, page - head); + set_page_private(head + SUBPAGE_INDEX_HWPOISON, page - head); } static inline void clear_subpage_hwpoison(struct page *head) { - set_page_private(head + 4, 0); + set_page_private(head + SUBPAGE_INDEX_HWPOISON, 0); } static int __init early_hugetlb_free_vmemmap_param(char *buf) @@ -2075,20 +2075,20 @@ 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]); } /* @@ -2100,17 +2100,17 @@ 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) -- 2.20.1