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 56826C433F5 for ; Mon, 29 Nov 2021 03:04:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242559AbhK2DIM (ORCPT ); Sun, 28 Nov 2021 22:08:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244829AbhK2DGL (ORCPT ); Sun, 28 Nov 2021 22:06:11 -0500 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42BD4C06175A for ; Sun, 28 Nov 2021 19:01:42 -0800 (PST) Received: by mail-pf1-x431.google.com with SMTP id x131so15256409pfc.12 for ; Sun, 28 Nov 2021 19:01:42 -0800 (PST) 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=zL2ulOJ65MyJYnIW0fWvJ/p3E9AOIPyCFtyEbbAkCqQ=; b=nAeEDuWhfLsRtR+CnqOTv19kQmKgj+7C3U7MbNrciHA2mhTJnq+T7KfO/f38P/AzEC Hlbh+VrManGSIxI/YDxacukAQKweebfDYzZAKZ81QBRkgxQwAjC4vV2KtQnmSVrazBH8 lLKS82rxiY/yzI3SppeisF6syoOGQX7TmMXHVe92TJj6YTu9WHxb06UHxozwaCzJx5Pp +M8dAqHMwW2YxHF5FwAujHKYbTTvUdJNFmEYT50w5qYb2ZRTbys0vNp4yURYJzQtvpsu 3tpaSNpBL8hQJ+6AnGQ/2vX8xwWoViLFUW/G6wcGgTUQ6pbRI3QSHdbr25tuKvyaaSEr c3RQ== 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=zL2ulOJ65MyJYnIW0fWvJ/p3E9AOIPyCFtyEbbAkCqQ=; b=W7NZqy+SEw54YX3BGW1ykw5ZlMRj5Fq4fw4Q52m8S9/GPdrJ62vauLLH8ekLLXw8gz KqFsmJD5bpVtkifWbyiumBiCwl2OOR6G5605XKuMmRzrzdL3CheVFTtie3/myGoxgBMD wmOj5AaC4dfzfyNg2cjn1NS8wLMoJTPICPRXhvgcJyjXtQgHiIRsxU4r0WNZeimdjUUR hJB9Qv1eZ8rShoUnQKhO6+YHZ+kZ9NPGUbOWbh4lGcWhEhFySTuS1muAdJi7uxQmxfpz dEAfSNO+GWhnV+EhqqZ8ucTw17sxBlNucfIHIzIUc/TW8HFLtgngQK95PnYlxysSsgmV /2cg== X-Gm-Message-State: AOAM530zGJBHS7kDvcyBbKebcZRsID7I26CRE+CwFjVANvzz4V9hBbVS Lm89yJ4LIw+zHumtODwSJFM= X-Google-Smtp-Source: ABdhPJzaJ6XcVRrcUF0rGeak2yUXxilR77+NGM2l0bsEGkOf8fyY1gGipEhRpU8auoQgOTa6QORS3Q== X-Received: by 2002:a63:8ac1:: with SMTP id y184mr30155915pgd.48.1638154901723; Sun, 28 Nov 2021 19:01:41 -0800 (PST) Received: from localhost.localdomain ([8.26.182.90]) by smtp.gmail.com with ESMTPSA id y23sm10066271pgf.86.2021.11.28.19.01.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 28 Nov 2021 19:01:41 -0800 (PST) From: Yanteng Si X-Google-Original-From: Yanteng Si To: corbet@lwn.net, alexs@kernel.org, bobwxc@email.cn, seakeel@gmail.com Cc: Yanteng Si , chenhuacai@kernel.org, jiaxun.yang@flygoat.com, linux-doc@vger.kernel.org, realpuyuwang@gmail.com, kolyshkin@gmail.com, changhuaixin@linux.alibaba.com, Yanteng Si Subject: [PATCH v2 1/3] docs/zh_CN: add scheduler sched-arch translation Date: Mon, 29 Nov 2021 11:00:21 +0800 Message-Id: <7a05bec2756bb4bf3843945166fa2d913677459c.1638154485.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 .../scheduler/sched-arch.rst into Chinese. Signed-off-by: Yanteng Si --- .../translations/zh_CN/scheduler/index.rst | 2 +- .../zh_CN/scheduler/sched-arch.rst | 78 +++++++++++++++++++ 2 files changed, 79 insertions(+), 1 deletion(-) create mode 100644 Documentation/translations/zh_CN/scheduler/sched-arch.rst diff --git a/Documentation/translations/zh_CN/scheduler/index.rst b/Documentation/translations/zh_CN/scheduler/index.rst index 5ec71e6043ae..797df3a9c66f 100644 --- a/Documentation/translations/zh_CN/scheduler/index.rst +++ b/Documentation/translations/zh_CN/scheduler/index.rst @@ -20,11 +20,11 @@ Linux调度器 :maxdepth: 1 completion + sched-arch TODOList: - sched-arch sched-bwc sched-deadline sched-design-CFS diff --git a/Documentation/translations/zh_CN/scheduler/sched-arch.rst b/Documentation/translations/zh_CN/scheduler/sched-arch.rst new file mode 100644 index 000000000000..0e02e7b5c9df --- /dev/null +++ b/Documentation/translations/zh_CN/scheduler/sched-arch.rst @@ -0,0 +1,78 @@ +.. include:: ../disclaimer-zh_CN.rst + +:Original: Documentation/scheduler/sched-arch.rst + +:翻译: + + 司延腾 Yanteng Si + +:校译: + + + +.. _cn_scheduler_sched-arch.rst: + +=============================== +架构特定代码的CPU调度器实现提示 +=============================== + + Nick Piggin, 2005 + +上下文切换 +========== +1. 运行队列锁 +默认情况下，switch_to arch函数在调用时锁定了运行队列。这通常不是一个问题，除非 +switch_to可能需要获取运行队列锁。这通常是由于上下文切换中的唤醒操作造成的。见 +arch/ia64/include/asm/switch_to.h的例子。 + +为了要求调度器在运行队列解锁的情况下调用switch_to，你必须在头文件 +中`#define __ARCH_WANT_UNLOCKED_CTXSW`(通常是定义switch_to的那个文件）。 + +在CONFIG_SMP的情况下，解锁的上下文切换对核心调度器的实现只带来了非常小的性能损 +失。 + +CPU空转 +======= +你的cpu_idle程序需要遵守以下规则： + +1. 现在抢占应该在空闲的例程上禁用。应该只在调用schedule()时启用，然后再禁用。 + +2. need_resched/TIF_NEED_RESCHED 只会被设置，并且在运行任务调用 schedule() + 之前永远不会被清除。空闲线程只需要查询need_resched，并且永远不会设置或清除它。 + +3. 当cpu_idle发现（need_resched() == 'true'），它应该调用schedule()。否则 + 它不应该调用schedule()。 + +4. 在检查need_resched时，唯一需要禁用中断的情况是，我们要让处理器休眠到下一个中 + 断（这并不对need_resched提供任何保护，它可以防止丢失一个中断）: + + 4a. 这种睡眠类型的常见问题似乎是:: + + local_irq_disable(); + if (!need_resched()) { + local_irq_enable(); + *** resched interrupt arrives here *** + __asm__("sleep until next interrupt"); + } + +5. 当need_resched变为高电平时，TIF_POLLING_NRFLAG可以由不需要中断来唤醒它们 + 的空闲程序设置。换句话说，它们必须定期轮询need_resched，尽管做一些后台工作或 + 进入低CPU优先级可能是合理的。 + + - 5a. 如果TIF_POLLING_NRFLAG被设置，而我们确实决定进入一个中断睡眠，那 + 么需要清除它，然后发出一个内存屏障（接着测试need_resched，禁用中断，如3中解释）。 + +arch/x86/kernel/process.c有轮询和睡眠空闲函数的例子。 + + +可能出现的arch/问题 +=================== + +我发现的可能的arch问题（并试图解决或没有解决）。: + +ia64 - safe_halt的调用与中断相比，是否很荒谬？ (它睡眠了吗) (参考 #4a) + +sh64 - 睡眠与中断相比，是否很荒谬？ (参考 #4a) + +sparc - 在这一点上，IRQ是开着的（？），把local_irq_save改为_disable。 + - 待办事项: 需要第二个CPU来禁用抢占 (参考 #1) -- 2.27.0