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=-16.7 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 D915AC433FE for ; Thu, 10 Dec 2020 04:00:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C3DC23BAC for ; Thu, 10 Dec 2020 04:00:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732255AbgLJEAG (ORCPT ); Wed, 9 Dec 2020 23:00:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732178AbgLJD77 (ORCPT ); Wed, 9 Dec 2020 22:59:59 -0500 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CD1DC0617A7 for ; Wed, 9 Dec 2020 19:59:19 -0800 (PST) Received: by mail-pg1-x544.google.com with SMTP id n1so243954pge.8 for ; Wed, 09 Dec 2020 19:59:19 -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=B+nJNAc14zNnwiniWCW6WfI6I2zFcqJ/51v3uWCVId4=; b=T5Wv4nmvP6rn0RpZ6Ot5g9vk07pjiLZeAI+i6y01lqwZzFeVImP7aVh2+2XA1v2b0O iAQGQ0QdK7BbEWuTCOxUHUABoB1FQGq2yq24jCXC1N386kFMPqz2CwqVFBL13CqGvSgD ezzEMwhNfwzdyGB7Ag3fsDM5e8Szzs+Zn3EU8jxy91czxPI2gYkvEs5hp2rqHzppKAi6 9SsdEER0ykXqhxdnC0MAzVlOVfv2WKXxl357TiD8iKKXl7nxR/nNMCjcW5C/ooXHTsZk Idl+mJRwAcjub4z0RZ6BEloHTb5Ho8QhrW9JcJ/y6sbgAMx+wHYyp5p7r8M/KE11Pw+q cAbw== 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=B+nJNAc14zNnwiniWCW6WfI6I2zFcqJ/51v3uWCVId4=; b=D85ARoJGhKctctBDGJRQD2RF74oUs/AeQg5giF+IOzETxpmTMPEdVFw6C7Htqqj2gf foMDUuRV22PIJquZCmq0btgWfOv54cj90P5bB0FUTOa7Rx6WZPOcizx7xy5MW0Vt5LkZ 4v+ZIL7Z/FTExfw06TXYu8Wg9rw/izH65WwgAcBfSpt3tpLJ7WKGsIDLs5aK+oBRZbBR iaze31LvdUwygRkhSTtnKI5ImkDG7T/m7mE2woW7fVPtip2oH+wkHBGdjSLe/jD8sge0 99GmXNjkDVLLtkmAA0G2LFrf73YOVtb4eft8O90lwlgEklXZwJChVygClQbx0GiQ46Nj xncQ== X-Gm-Message-State: AOAM531fw9/C6J5iUjfJTMTBSHw+zrpP+slqWQw9IWELJIIvLVw2UrMN 92ba8GV+kOkBG7jnojqw/+7hLA== X-Google-Smtp-Source: ABdhPJx/JWypShgKNhyFcLhmO2UkTLBOKi94hUOjTvzflK5/8tNJ4r+p3oe5V3QFJhzi0PIAGpI3TQ== X-Received: by 2002:a17:90b:4a0d:: with SMTP id kk13mr5302197pjb.23.1607572758963; Wed, 09 Dec 2020 19:59:18 -0800 (PST) Received: from localhost.localdomain ([103.136.220.85]) by smtp.gmail.com with ESMTPSA id f33sm4266535pgl.83.2020.12.09.19.59.08 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Dec 2020 19:59:18 -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 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 v8 11/12] mm/hugetlb: Gather discrete indexes of tail page Date: Thu, 10 Dec 2020 11:55:25 +0800 Message-Id: <20201210035526.38938-12-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20201210035526.38938-1-songmuchun@bytedance.com> References: <20201210035526.38938-1-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. 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 --- 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 6440367a71b6..e38fee45afd3 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1361,7 +1361,7 @@ static inline void subpage_hwpoison_deliver(struct hstate *h, struct page *head) return; if (PageHWPoison(head)) - 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, @@ -1380,7 +1380,7 @@ static inline void set_subpage_hwpoison(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); return; } @@ -1460,20 +1460,20 @@ 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]); } /* @@ -1485,17 +1485,17 @@ 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 36a2e2db7913..7f0b9e002be4 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -427,6 +427,14 @@ 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)); + /* We cannot optimize if a "struct page" crosses page boundaries. */ if (!is_power_of_2(sizeof(struct page))) return; -- 2.11.0