From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 F2F91537E6; Tue, 9 Apr 2024 07:25:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712647544; cv=none; b=e7+gSWERbvo3Yw+R0fArG+bd15yMlShp67iQw+dL/+B0ZJgK3LuILwXW5EjnPbcTy9Ovu7jHQ3J4Apiwuf8qaeg8nevbSZR+fAa5CUXkdTDg45y6Me2kuCvqPaYaIjBRufrfFMOHrfrpjC9zSUIDvW+pQDBoXf0NTp5ndriy5Sc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712647544; c=relaxed/simple; bh=9x+TfeQHYbAC2ZOOl4tIe41PHvzWIyJ7rn56eOmWHqI=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=qhMcgLW6KH6Sp9KO7wuuJow2mJnyYKjR8nC8aayUcVz2FUVKt2Xq/W278g1QYStPVk6ZXo2R2t+ADrfz85rcPj3/BgH+Xvk8YTB9bCnDHBk+4uHrucFeOrjjFc5MkjDq1xp6cMm8WatddtxWglzBTTPy3dFa2IjF82eOKV9HDyg= 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=45.249.212.187 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 [172.19.162.254]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4VDHVD6BvczwRVJ; Tue, 9 Apr 2024 15:22:44 +0800 (CST) Received: from canpemm500001.china.huawei.com (unknown [7.192.104.163]) by mail.maildlp.com (Postfix) with ESMTPS id 1F11218007D; Tue, 9 Apr 2024 15:25:39 +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; Tue, 9 Apr 2024 15:25:38 +0800 Message-ID: Date: Tue, 9 Apr 2024 15:25:38 +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: CC: , , , , Steven Rostedt , Peter Zijlstra References: <20240131123238.2332064-1-zhangqiao22@huawei.com> From: Zhang Qiao In-Reply-To: <20240131123238.2332064-1-zhangqiao22@huawei.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500001.china.huawei.com (7.192.104.163) Ping. +cc Peter, Steven. 在 2024/1/31 20:32, Zhang Qiao 写道: > RT_RUNTIME_SHARE is an important strategy for rt bandwidth, and > we should document this sched feature. > > Signed-off-by: Zhang Qiao > --- > Documentation/scheduler/sched-rt-group.rst | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/Documentation/scheduler/sched-rt-group.rst b/Documentation/scheduler/sched-rt-group.rst > index d685609ed3d7..4d8eceb71f5e 100644 > --- a/Documentation/scheduler/sched-rt-group.rst > +++ b/Documentation/scheduler/sched-rt-group.rst > @@ -12,6 +12,7 @@ Real-Time group scheduling > 2.1 System-wide settings > 2.2 Default behaviour > 2.3 Basis for grouping tasks > + 2.4 RT_RUNTIME_SHARE sched feature > 3. Future plans > > > @@ -146,6 +147,16 @@ 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. > + > +With this feature enabled, a rt-task probably hits 100% cpu usage and starves > +per-cpu tasks like kworkers, as a result, it may hang up the whole system. > +Therefore, in order to avoid such exception, recommand to disable this feature > +by default unless you really know what you're up to. > > 3. Future plans > =============== >