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=-16.8 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 D49B0C4332B for ; Mon, 8 Mar 2021 10:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9E01651A5 for ; Mon, 8 Mar 2021 10:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231224AbhCHKcM (ORCPT ); Mon, 8 Mar 2021 05:32:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231486AbhCHKb7 (ORCPT ); Mon, 8 Mar 2021 05:31:59 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75AA8C06175F for ; Mon, 8 Mar 2021 02:31:59 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id b15so2778425pjb.0 for ; Mon, 08 Mar 2021 02:31:59 -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=gfGqu+49Niws0forzteRw4jFnXBXurIKUuBD2g5ekl8=; b=M+gvc4FFfSh+WU/Y4Va+z7STO1hnPOimMX5cZOZwlKP5Ln/vSez3XYrj80JsOsy0hJ yD+2GGzA3RzR4LxNZf1SNsjEpdTD/MsN72X+hpycKBJOFUD/CAdE/2youJ7LjE2QSH0F n+UobDlujMZeCU5pjvw9oac0PDYD9JycJupv+Ochcfk2i9ZGrDfkm0yJ3H58RDlNE2SK vaomlN2kIlIZls/c87v9LRnfVJF4uggS8hNDKMnGl2a9F6mz1qnbNQcKlX4sIewLJUhW d5FRBu2ljqmHK8Rs8jMW1VV9vhwk4NfSJuPulFRc1IDkYwYd2Pypk2VAJu9ZhoZVbsXJ sLUw== 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=gfGqu+49Niws0forzteRw4jFnXBXurIKUuBD2g5ekl8=; b=KZBCtsryDpyJgFGlWwRyelPcWlTzBI8U5L1RpVZN7YhLulf1LKe0TNkOcmddbabJMY ZMeh7JpRe7HXR5tiZ7+Ygcm8g0N+kRl0qZaywrd89osOsYun2AjGo5ELJWzov/pKBlwZ H37w9vD6u1GOmuDc8bU9SKyfAD6pHLNlDh0OCw08xRZh1V8PyEAUrRrBcl+jCwaJDkGd 2EKazMp3+5/arAZjiLkyPeZlNKdQ5zv7qCRyuaYAS+b3nlcly11TIh08oaHAIJovVF4R fK7X9jWNRNoEOzIVS8P2Fs9kyVq8mGCF8IcthAQTqR72ozEvxZmt5w21YXWgzqDPkB0w 5cZQ== X-Gm-Message-State: AOAM531H8Tq4rewI4R1NQNP0UFncKLisozqkao9v4UTGHH5jbgC7MKsH 85X1zc2lbtCATQycF7Kl1r58lQ== X-Google-Smtp-Source: ABdhPJyE+Y/9Z9zO5sdEC6r9Qv6P5x7yp6cmXzuURerBPQdEqNd4x4HKG+ACfEy5/7tPgBu5D3j8Tg== X-Received: by 2002:a17:903:31c4:b029:e1:8840:8ab9 with SMTP id v4-20020a17090331c4b02900e188408ab9mr20235017ple.70.1615199519063; Mon, 08 Mar 2021 02:31:59 -0800 (PST) Received: from localhost.localdomain ([139.177.225.255]) by smtp.gmail.com with ESMTPSA id ge16sm10744705pjb.43.2021.03.08.02.31.47 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Mar 2021 02:31:58 -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, joao.m.martins@oracle.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 , Chen Huang , Bodeddula Balasubramaniam Subject: [PATCH v18 8/9] mm: hugetlb: gather discrete indexes of tail page Date: Mon, 8 Mar 2021 18:28:06 +0800 Message-Id: <20210308102807.59745-9-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210308102807.59745-1-songmuchun@bytedance.com> References: <20210308102807.59745-1-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 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 Tested-by: Chen Huang Tested-by: Bodeddula Balasubramaniam --- include/linux/hugetlb.h | 24 ++++++++++++++++++++++-- include/linux/hugetlb_cgroup.h | 19 +++++++++++-------- mm/hugetlb.c | 6 +++--- mm/hugetlb_vmemmap.c | 8 ++++++++ 4 files changed, 44 insertions(+), 13 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index a4d80f7263fc..c70421e26189 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -28,6 +28,26 @@ 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 */ + __MAX_CGROUP_SUBPAGE_INDEX = SUBPAGE_INDEX_CGROUP_RSVD, +#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; @@ -607,13 +627,13 @@ 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..54ec689e3c9c 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(__MAX_CGROUP_SUBPAGE_INDEX + 1) -#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.c b/mm/hugetlb.c index c221b937be17..4956880a7861 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1312,7 +1312,7 @@ 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, @@ -1331,7 +1331,7 @@ 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, @@ -1347,7 +1347,7 @@ static inline void hwpoison_subpage_clear(struct hstate *h, struct page *head) if (!PageHWPoison(head) || !free_vmemmap_pages_per_hpage(h)) return; - set_page_private(head + 4, 0); + set_page_private(head + SUBPAGE_INDEX_HWPOISON, 0); } #else static inline void hwpoison_subpage_deliver(struct hstate *h, struct page *head) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index b65f0d5189bd..33e42678abe3 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -257,6 +257,14 @@ 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; -- 2.11.0