From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B6AB6F9CD; Fri, 19 Apr 2024 08:52:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713516739; cv=none; b=W44DOny6MF+TdgvHx02ZhWAFtFjwYTl6wUJikJ4LCNiZsmWnwfR3sjlhxFBLVXzow5W0Btd9g3//UD6EUg9FkjqLVgFSBTXpqQCJudw/iM2MJe/YtUvVnDd+dtBYLxj9LhDprq5m/CFRWxfNHp7UfP8O4Gh0M4tD43yGdyUvvtg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713516739; c=relaxed/simple; bh=4FFnkWokSaQu1tit/8C9PTelyo7m8d+6FKp7oVIIVp8=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=AtVVnFeRz55wJ+Engl8ban69mbENE/poNf10Jy52fc6SfaEKwAkvbFLZJd7g/8bDjR01LbmtN1VvhLqJ1Kikn1KfsJ56O5flENHZxfqC2SGpKHHxOsjN03iaKoTIHA35//LzZXcAILgKow8uqcVARPX9tsPozpOwO0N5hBWI79Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.252]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4VLSxz1dkBzNsmw; Fri, 19 Apr 2024 16:49:43 +0800 (CST) Received: from canpemm500001.china.huawei.com (unknown [7.192.104.163]) by mail.maildlp.com (Postfix) with ESMTPS id 15EEB18007E; Fri, 19 Apr 2024 16:52:09 +0800 (CST) Received: from [10.67.111.186] (10.67.111.186) by canpemm500001.china.huawei.com (7.192.104.163) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Fri, 19 Apr 2024 16:51:56 +0800 Message-ID: Date: Fri, 19 Apr 2024 16:51:56 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.1.1 Subject: Re: [PATCH] sched/Documentation: Add RT_RUNTIME_SHARE documentation To: Bagas Sanjaya CC: , , , , Steven Rostedt , Peter Zijlstra , References: <20240131123238.2332064-1-zhangqiao22@huawei.com> From: Zhang Qiao In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500001.china.huawei.com (7.192.104.163) 在 2024/4/12 10:50, Bagas Sanjaya 写道: > On Wed, Jan 31, 2024 at 08:32:38PM +0800, Zhang Qiao wrote: >> +2.4 RT_RUNTIME_SHARE sched feature >> +---------------------------- > > htmldocs build reports new warning: > > Documentation/scheduler/sched-rt-group.rst:151: WARNING: Title underline too short. > > 2.4 RT_RUNTIME_SHARE sched feature > ---------------------------- > > I have to extend the underline: > > ---- >8 ---- > diff --git a/Documentation/scheduler/sched-rt-group.rst b/Documentation/scheduler/sched-rt-group.rst > index 4d8eceb71f5ed8..751113fcd35850 100644 > --- a/Documentation/scheduler/sched-rt-group.rst > +++ b/Documentation/scheduler/sched-rt-group.rst > @@ -148,7 +148,7 @@ For now, this can be simplified to just the following (but see Future plans): > \Sum_{i} runtime_{i} <= global_runtime > > 2.4 RT_RUNTIME_SHARE sched feature > ----------------------------- > +---------------------------------- > > RT_RUNTIME_SHARE allows a cpu borrows rt-runtime from other cpus if it runs > out of its own rt-runtime. > > Wording suggestions below. Hi, Bagas， Thanks for you suggestions, i will update in v2. Zhang Qiao. > >> + >> +RT_RUNTIME_SHARE allows a cpu borrows rt-runtime from other cpus if it runs > "... to borrow rt-runtime ..." >> +out of its own rt-runtime. >> + >> +With this feature enabled, a rt-task probably hits 100% cpu usage and starves > "... a rt-task may hit ... and can stall other per-cpu tasks ..." >> +per-cpu tasks like kworkers, as a result, it may hang up the whole system. > "..., which lead into system hang." >> +Therefore, in order to avoid such exception, recommand to disable this feature >> +by default unless you really know what you're up to. > "Thus, it is advised to disable this feature by default to avoid aforementioned > issue unless you know what you're doing." > > Thanks. >