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 CB80DC64E7A for ; Fri, 20 Nov 2020 06:47:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B72B22404 for ; Fri, 20 Nov 2020 06:47:03 +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="VmrGqdVE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726454AbgKTGrA (ORCPT ); Fri, 20 Nov 2020 01:47:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726334AbgKTGq7 (ORCPT ); Fri, 20 Nov 2020 01:46:59 -0500 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C3AFC061A48 for ; Thu, 19 Nov 2020 22:46:58 -0800 (PST) Received: by mail-pg1-x542.google.com with SMTP id q34so6466226pgb.11 for ; Thu, 19 Nov 2020 22:46:58 -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=88Vyf1Pcm29kb9drVzemkW2MmMhaFRrGbBNvTcfU0mI=; b=VmrGqdVEOmmHQIibPHpVJJjw83uIZZNbNV7ajzRc+ac94AKkBDewjWcEn0w1pLdNww SYgU3lDsbdUs2nBjB9CVxNVWksSQOgZSz7RhoKAsntzXOatfNxp/bnOl96fstM6HxRWc Qw55+TZP9tbhXQXk7PXbT3kZFCGah5DtZGIH2jzYKhqRynAxkqd+qkdAPrV/wo8sBlhw 5V1y3bMzOQSzjsuoyXb5S74L1+IlvSnynuGzUEpYLTQJy1tZjK0CxMF9LfsMR2ILa70e Fpc7/r2DvD1XMTOSAbac2R+eixL4bGYtNgC6cBB2bYxFmZ0F5CgUSwqb6xIeeGSJ7a70 7dFQ== 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=88Vyf1Pcm29kb9drVzemkW2MmMhaFRrGbBNvTcfU0mI=; b=njM/xHo1hH0cEcMTYGURX47z0EAjRiKJPMhLk2Zl7AnfRLLUig7SZOlvVTWb4X+PMb 1dqPFJ3YrRVQzvka58LvSjMWp51UPiH7ceKYTSkKBiNGmboxG2nGnI1qQCy6aXieLTxQ uU0I8y/NmzbrgIGTcnE+++f+Ji3XfxjDhSExgu8VHsJRA5LiWWll2F6MXaFyHlSmCc8l +3S6IvjkPYF8KLH/MHaZeYXYTgBV4TXMUKuzlPjeEauo5wrSaprK65eSLtk4Sb3NEg3b Pn9dZYEZIZUSdgDlfritiGoJ7iBJNmbqHse1/iz0kA+uqooaazG5cpggR764UJKO2G0a WDOw== X-Gm-Message-State: AOAM530nQBDRJnLVgn01N7Ujckhj0sJOH0vBYsQhdbfdGe5uDDveAGfo wMBix4Pj7G2jLtbKi6LAUjQ99Q== X-Google-Smtp-Source: ABdhPJyA2pbz2sUo0O1TKkJnOt8g0Z0zF62vjdl9xLhDjvD5IAhMOMWolvPOKpNYn7tiG+C8sefhJw== X-Received: by 2002:aa7:8552:0:b029:18e:f030:e514 with SMTP id y18-20020aa785520000b029018ef030e514mr12036552pfn.2.1605854818095; Thu, 19 Nov 2020 22:46:58 -0800 (PST) Received: from localhost.localdomain ([103.136.221.72]) by smtp.gmail.com with ESMTPSA id 23sm2220278pfx.210.2020.11.19.22.46.48 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 Nov 2020 22:46:57 -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 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 v5 05/21] mm/hugetlb: Introduce pgtable allocation/freeing helpers Date: Fri, 20 Nov 2020 14:43:09 +0800 Message-Id: <20201120064325.34492-6-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20201120064325.34492-1-songmuchun@bytedance.com> References: <20201120064325.34492-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On x86_64, vmemmap is always PMD mapped if the machine has hugepages support and if we have 2MB contiguous pages and PMD alignment. If we want to free the unused vmemmap pages, we have to split the huge PMD firstly. So we should pre-allocate pgtable to split PMD to PTE. Signed-off-by: Muchun Song Suggested-by: Oscar Salvador Acked-by: Mike Kravetz --- mm/hugetlb_vmemmap.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++ mm/hugetlb_vmemmap.h | 11 ++++++++ 2 files changed, 87 insertions(+) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 1afe245395e5..ec70980000d8 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -99,6 +99,8 @@ */ #define pr_fmt(fmt) "HugeTLB Vmemmap: " fmt +#include +#include #include "hugetlb_vmemmap.h" /* @@ -111,6 +113,80 @@ */ #define RESERVE_VMEMMAP_NR 2U +#ifndef VMEMMAP_HPAGE_SHIFT +#define VMEMMAP_HPAGE_SHIFT HPAGE_SHIFT +#endif +#define VMEMMAP_HPAGE_ORDER (VMEMMAP_HPAGE_SHIFT - PAGE_SHIFT) +#define VMEMMAP_HPAGE_NR (1 << VMEMMAP_HPAGE_ORDER) +#define VMEMMAP_HPAGE_SIZE ((1UL) << VMEMMAP_HPAGE_SHIFT) +#define VMEMMAP_HPAGE_MASK (~(VMEMMAP_HPAGE_SIZE - 1)) + +static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) +{ + return h->nr_free_vmemmap_pages; +} + +static inline unsigned int vmemmap_pages_per_hpage(struct hstate *h) +{ + return free_vmemmap_pages_per_hpage(h) + RESERVE_VMEMMAP_NR; +} + +static inline unsigned long vmemmap_pages_size_per_hpage(struct hstate *h) +{ + return (unsigned long)vmemmap_pages_per_hpage(h) << PAGE_SHIFT; +} + +static inline unsigned int pgtable_pages_to_prealloc_per_hpage(struct hstate *h) +{ + unsigned long vmemmap_size = vmemmap_pages_size_per_hpage(h); + + /* + * No need pre-allocate page tables when there is no vmemmap pages + * to free. + */ + if (!free_vmemmap_pages_per_hpage(h)) + return 0; + + return ALIGN(vmemmap_size, VMEMMAP_HPAGE_SIZE) >> VMEMMAP_HPAGE_SHIFT; +} + +void vmemmap_pgtable_free(struct page *page) +{ + struct page *pte_page, *t_page; + + list_for_each_entry_safe(pte_page, t_page, &page->lru, lru) { + list_del(&pte_page->lru); + pte_free_kernel(&init_mm, page_to_virt(pte_page)); + } +} + +int vmemmap_pgtable_prealloc(struct hstate *h, struct page *page) +{ + unsigned int nr = pgtable_pages_to_prealloc_per_hpage(h); + + /* + * Use the huge page lru list to temporarily store the preallocated + * pages. The preallocated pages are used and the list is emptied + * before the huge page is put into use. When the huge page is put + * into use by prep_new_huge_page() the list will be reinitialized. + */ + INIT_LIST_HEAD(&page->lru); + + while (nr--) { + pte_t *pte_p; + + pte_p = pte_alloc_one_kernel(&init_mm); + if (!pte_p) + goto out; + list_add(&virt_to_page(pte_p)->lru, &page->lru); + } + + return 0; +out: + vmemmap_pgtable_free(page); + return -ENOMEM; +} + void __init hugetlb_vmemmap_init(struct hstate *h) { unsigned int order = huge_page_order(h); diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h index 40c0c7dfb60d..9eca6879c0a4 100644 --- a/mm/hugetlb_vmemmap.h +++ b/mm/hugetlb_vmemmap.h @@ -12,9 +12,20 @@ #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP void __init hugetlb_vmemmap_init(struct hstate *h); +int vmemmap_pgtable_prealloc(struct hstate *h, struct page *page); +void vmemmap_pgtable_free(struct page *page); #else static inline void hugetlb_vmemmap_init(struct hstate *h) { } + +static inline int vmemmap_pgtable_prealloc(struct hstate *h, struct page *page) +{ + return 0; +} + +static inline void vmemmap_pgtable_free(struct page *page) +{ +} #endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */ #endif /* _LINUX_HUGETLB_VMEMMAP_H */ -- 2.11.0