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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31ED7C4332F for ; Mon, 28 Mar 2022 09:59:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240120AbiC1KAz (ORCPT ); Mon, 28 Mar 2022 06:00:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240115AbiC1KAy (ORCPT ); Mon, 28 Mar 2022 06:00:54 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 419924130B for ; Mon, 28 Mar 2022 02:59:13 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id c15-20020a17090a8d0f00b001c9c81d9648so237983pjo.2 for ; Mon, 28 Mar 2022 02:59:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=AAvJxMQEEM61ZcW5e/1wHe2yd4Fqe2CFep9x6YNicM8=; b=aZctRTu7+o3DyY7LrvvtocoXxKjusDyLu02BZAjeYRHCwAQk5zwx48p5wVNcR4dNcH 0U2+8h0j6NvOI3M0OCgmGb7O7ysrNOwgIcgRb9lxvUcvqlPG+Uy3iFDql2rSFcZOznwq 0fmkE/NLoqhIIgtsCZoOAk9PpeXu3JGIMQkpeK2zagfv/2n5toVj9TdywHFj+LcrWQrV x63oqRZFXfguEApOgQtImlmTmmYBYlNfFfIPwumG908DnIvKLAgP2P8CUMGjMvIKgh96 enZwdrLuJMXfSMmJ66/IZdMs57hXeD+7umVmlsZjMg5/ohngvVMQka/PJg+gF3k1+mEP DfXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=AAvJxMQEEM61ZcW5e/1wHe2yd4Fqe2CFep9x6YNicM8=; b=hw4oGGfjML67sHtEFolC2MhqM9N23NYSM6D0T8UG4xx4cumUns19Iz2SsHhluUmI3f miGoWEbHKBJ+JFdefuMWuhhn2vwWbzdBIFsYb7LVVQhMFbOEdOkzPPWXribjXEr3DUKA y4yrDGxO8d1athEQLC1ZfBVwGV1j3UpDeKrqHZNx2mXCDMFv4sxb8zebvXk2aMq12maV AvIPTjEmmuk63ge2Kea0nmaGEJ/HeJvOdKnOKlBH4/1+SLEOKO+Hb6ejIzbB7xMMizP3 F+WjtktlDyABvuq+Ydj6V2lQ4ziN9D3Prp6HqllWHEAt9Q+m+4gPfTFNKYZVY+353F8S dkHg== X-Gm-Message-State: AOAM533GEgX9wNFjPrWaGbhtYd9Gia4781rib/T0xWwBjYpyflnhRKBo sqKxaL6xkKnsMeAciI0vwyc= X-Google-Smtp-Source: ABdhPJxa9/fMJDUCuXF5zhs48ohlrYZoarQJNUilisH0Y/Y3IWKC4/fXVyPcXPe6Fvd5/yBvqVZDkg== X-Received: by 2002:a17:90b:4ac1:b0:1c7:7e32:4ec4 with SMTP id mh1-20020a17090b4ac100b001c77e324ec4mr27376941pjb.85.1648461553432; Mon, 28 Mar 2022 02:59:13 -0700 (PDT) Received: from localhost.localdomain (111-250-2-155.dynamic-ip.hinet.net. [111.250.2.155]) by smtp.gmail.com with ESMTPSA id 8-20020a17090a174800b001c7d8b160f0sm10526637pjm.51.2022.03.28.02.59.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Mar 2022 02:59:13 -0700 (PDT) From: Yanteng Si X-Google-Original-From: Yanteng Si To: corbet@lwn.net, alexs@kernel.org, seakeel@gmail.com Cc: Yanteng Si , chenhuacai@kernel.org, jiaxun.yang@flygoat.com, linux-doc@vger.kernel.org, Yanteng Si Subject: [PATCH v3 09/12] docs/zh_CN: add vm remap_file_pages translation Date: Mon, 28 Mar 2022 17:59:51 +0800 Message-Id: <265cf95bcfc28f94c40b01e8c0c6d191fcdcbe45.1648458742.git.siyanteng@loongson.cn> X-Mailer: git-send-email 2.27.0 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Yanteng Si Translate .../vm/remap_file_pages.rst into Chinese. Signed-off-by: Yanteng Si Reviewed-by: Alex Shi --- Documentation/translations/zh_CN/vm/index.rst | 2 +- .../zh_CN/vm/remap_file_pages.rst | 32 +++++++++++++++++++ 2 files changed, 33 insertions(+), 1 deletion(-) create mode 100644 Documentation/translations/zh_CN/vm/remap_file_pages.rst diff --git a/Documentation/translations/zh_CN/vm/index.rst b/Documentation/translations/zh_CN/vm/index.rst index a2dea8b618ad..3e4f4cac509c 100644 --- a/Documentation/translations/zh_CN/vm/index.rst +++ b/Documentation/translations/zh_CN/vm/index.rst @@ -35,6 +35,7 @@ TODO:待引用文档集被翻译完毕后请及时修改此处） page_frags page_owner page_table_check + remap_file_pages TODOLIST: * arch_pgtable_helpers @@ -43,7 +44,6 @@ TODOLIST: * hugetlbfs_reserv * numa * page_migration -* remap_file_pages * slub * split_page_table_lock * transhuge diff --git a/Documentation/translations/zh_CN/vm/remap_file_pages.rst b/Documentation/translations/zh_CN/vm/remap_file_pages.rst new file mode 100644 index 000000000000..af6b7e28af23 --- /dev/null +++ b/Documentation/translations/zh_CN/vm/remap_file_pages.rst @@ -0,0 +1,32 @@ +:Original: Documentation/vm/remap_file_pages.rst + +:翻译: + + 司延腾 Yanteng Si + +:校译: + + +============================== +remap_file_pages()系统调用 +============================== + +remap_file_pages()系统调用被用来创建一个非线性映射，也就是说，在这个映射中， +文件的页面被无序映射到内存中。使用remap_file_pages()比重复调用mmap(2)的好 +处是，前者不需要内核创建额外的VMA（虚拟内存区）数据结构。 + +支持非线性映射需要在内核虚拟内存子系统中编写大量的non-trivial的代码，包括热 +路径。另外，为了使非线性映射工作，内核需要一种方法来区分正常的页表项和带有文件 +偏移的项（pte_file）。内核为达到这个目的在PTE中保留了标志。PTE标志是稀缺资 +源，特别是在某些CPU架构上。如果能腾出这个标志用于其他用途就更好了。 + +幸运的是，在生活中并没有很多remap_file_pages()的用户。只知道有一个企业的RDBMS +实现在32位系统上使用这个系统调用来映射比32位虚拟地址空间线性尺寸更大的文件。 +由于64位系统的广泛使用，这种使用情况已经不重要了。 + +syscall被废弃了，现在用一个模拟来代替它。仿真会创建新的VMA，而不是非线性映射。 +对于remap_file_pages()的少数用户来说，它的工作速度会变慢，但ABI被保留了。 + +仿真的一个副作用（除了性能之外）是，由于额外的VMA，用户可以更容易达到 +vm.max_map_count的限制。关于限制的更多细节，请参见DEFAULT_MAX_MAP_COUNT +的注释。 -- 2.27.0