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 3C19EC6FA82 for ; Sat, 3 Sep 2022 07:10:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232851AbiICHKb (ORCPT ); Sat, 3 Sep 2022 03:10:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbiICHK2 (ORCPT ); Sat, 3 Sep 2022 03:10:28 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4D11A5A146; Sat, 3 Sep 2022 00:10:26 -0700 (PDT) Received: from [192.168.100.8] (unknown [112.20.110.237]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Cx72vY_RJjzl0QAA--.891S3; Sat, 03 Sep 2022 15:10:17 +0800 (CST) Message-ID: <34c19e49-1752-9d8c-0766-2f55416c2f10@loongson.cn> Date: Sat, 3 Sep 2022 15:10:10 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: [PATCH] Documentation/zh_CN: add latest kmap_local_page translation To: Zhao Liu , Alex Shi , Jonathan Corbet , Wu XiangCheng , Mike Rapoport , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ira Weiny , "Fabio M . De Francesco" , Zhenyu Wang , Zhao Liu References: <20220902081304.2259706-1-zhao1.liu@linux.intel.com> From: YanTeng Si In-Reply-To: <20220902081304.2259706-1-zhao1.liu@linux.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID: AQAAf8Cx72vY_RJjzl0QAA--.891S3 X-Coremail-Antispam: 1UD129KBjvJXoWxWF13Ww1ktF43KryDCw13XFb_yoWrAFyxpF 929ry2gw43A342v3ySg342v3WrJ3W7GF42kFW7JasrX398A39Yy3y7KF98X3Z7Z3s7CFWx ArWUurn5Ar909wUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9mb7Iv0xC_Cr1lb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_JFI_Gr1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwV C2z280aVCY1x0267AKxVWxJr0_GcWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xv F2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r 4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvEwIxGrwACI402YVCY1x02628vn2kIc2xK xwCYjI0SjxkI62AI1cAE67vIY487MxkIecxEwVAFwVW8CwCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IY s7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr 0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07j0g4fUUUUU= X-CM-SenderInfo: pvl1t0pwhqwqxorr0wxvrqhubq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022/9/2 16:13, Zhao Liu 写道: > From: Zhao Liu > > Translate the lastest description of kmap_local_page into Chinese. > > The translation is based on these commits: > > commit 516ea046ec555 ("Documentation/mm: don't kmap*() pages which > can't come from HIGHMEM") > > commit 6b3afe2eeec27 ("Documentation/mm: avoid invalid use of > addresses from kmap_local_page()") > > commit 84b86f6054c42 ("Documentation/mm: rrefer kmap_local_page() > and avoid kmap()") > > commit a9e9c93966afd ("Documentation/mm: add details about > kmap_local_page() and preemption") > > Suggested-by: Ira Weiny > Suggested-by: Fabio M. De Francesco > Signed-off-by: Zhao Liu Acked-by: Yanteng Si > --- > Suggested by credits. > Ira: Referred to his task document. > Fabio: Referred to his work on the original English document. > > --- > .../translations/zh_CN/mm/highmem.rst | 20 ++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) > > diff --git a/Documentation/translations/zh_CN/mm/highmem.rst b/Documentation/translations/zh_CN/mm/highmem.rst > index f74800a6d9a7..ac4c86ed74d8 100644 > --- a/Documentation/translations/zh_CN/mm/highmem.rst > +++ b/Documentation/translations/zh_CN/mm/highmem.rst > @@ -58,14 +58,28 @@ > 在可行的情况下，这个函数应该比其他所有的函数优先使用。 > > 这些映射是线程本地和CPU本地的，这意味着映射只能从这个线程中访问，并且当映射处于活动状 > - 态时，该线程与CPU绑定。即使线程被抢占了（因为抢占永远不会被函数禁用），CPU也不能通过 > - CPU-hotplug从系统中拔出，直到映射被处理掉。 > + 态时，该线程与CPU绑定。即使抢占永远不会被这个函数禁用，CPU也不能通过CPU-hotplug从系 > + 统中拔出，直到映射被处理掉。 > > - 在本地的kmap区域中采取pagefaults是有效的，除非获取本地映射的上下文由于其他原因不允许 > + 在本地的kmap区域中获取pagefaults是有效的，除非获取本地映射的上下文由于其他原因不允许 > 这样做。 > > + 如前所述，pagefault和抢占永远不会被禁用。不需要禁用抢占，因为当上下文切换到不同的任务 > + 时，传出任务的映射会被保存，而传入任务的映射会被恢复。 > + > kmap_local_page()总是返回一个有效的虚拟地址，并且假定kunmap_local()不会失败。 > > + 在CONFIG_HIGHMEM=n内核和低内存页面上，这将返回直接映射的虚拟地址。只有真正的高内存页 > + 面会被临时映射。因此，用户可以为已知不是来自ZONE_HIGHMEM的页面调用普通的 > + page_address()，但是，使用kmap_local_page() / kunmap_local()总是安全的。 > + > + 虽然它比kmap()快得多，但对于高内存情况，它带有指针有效性的限制。和kmap()映射相反，本地 > + 映射仅在调用者的上下文中有效，并不能被交给其他的上下文。这意味着用户必须绝对确保返回的地址 > + 仅在映射它的线程的本地使用。 > + > + 大多数代码可以设计为使用线程本地映射。因此，用户应该尝试这样去设计他们的代码，在地址会被使 > + 用的同一线程中映射页面来避免使用kmap()，并且更倾向于去使用kmap_local_page()。 > + > 嵌套kmap_local_page()和kmap_atomic()映射在一定程度上是允许的（最多到KMAP_TYPE_NR）， > 但是它们的调用必须严格排序，因为映射的实现是基于堆栈的。关于如何管理嵌套映射的细节， > 请参见kmap_local_page() kdocs（包含在 "函数 "部分）。