From patchwork Wed Jan 17 16:35:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 13522020 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 E0CA723768 for ; Wed, 17 Jan 2024 16:36:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705509386; cv=none; b=gHQaWRRxlkgl3F4Hai/BNVp0G4wzw66nK2QBqVvpFE8nEjh1fdNototECI+rJopTyR4Widjkn6178xdvqhTptAoTEFvJWQLRQz7IFyMf5Jdy43Zgi3Po5KhbW78lIdH2tifFserlYSp7EYqfIvbiaqww42krZtGNCZPyELt2SsU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705509386; c=relaxed/simple; bh=i0Ofa11RRO77lr53R6C5icaSmSfpdwG1dq7E5sm7z1M=; h=DKIM-Signature:Received:X-MC-Unique:Received:Received:From:To:Cc: Subject:Date:Message-Id:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-Scanned-By; b=X3BiffW1b+nHRPN8UZHsMX3Gj+FnB0ut2WyNuQlxy62IJ4H0yXPcWmUqRuQRlctx8HeIl3I432IZYzmBSM+GRwy5Kdm3ZhFDrjMzdxM4eQssSsX18PZzXarwAuORbtFXZRZPYXnyQZGLo7yt0nYTCNxgtzFU8hElujcogthOC/Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Vr4Q12Fv; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Vr4Q12Fv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705509384; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KotaQECG6rJbRoU9m6xm3uHY0VUggl9xjizYviPB8yA=; b=Vr4Q12FvLeIGDRgD6f/rn2TcoweO9rn1+pGl7BHNRGPHIp8C8S7eN1+Cm5E3d1TWFJojmr 3l4nsv9mHu3ENjkPIvZZUaOYQqDC8+maVl24S+BWUyMe7m2TXstcN00KAzGeWQLPvx9Ncv 7JzDAvpQfAcOAZP/Y+6sx7Wejyq/SJw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-450-P98TlzovNymX4FjnA35Hcg-1; Wed, 17 Jan 2024 11:36:18 -0500 X-MC-Unique: P98TlzovNymX4FjnA35Hcg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7FDC4185A7A8; Wed, 17 Jan 2024 16:36:16 +0000 (UTC) Received: from llong.com (unknown [10.22.16.147]) by smtp.corp.redhat.com (Postfix) with ESMTP id D1B9F1121306; Wed, 17 Jan 2024 16:36:14 +0000 (UTC) From: Waiman Long To: Tejun Heo , Zefan Li , Johannes Weiner , Frederic Weisbecker , Jonathan Corbet , "Paul E. McKenney" , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Davidlohr Bueso , Shuah Khan Cc: cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-kselftest@vger.kernel.org, Mrunal Patel , Ryan Phillips , Brent Rowsell , Peter Hunt , Cestmir Kalina , Nicolas Saenz Julienne , Alex Gladkov , Marcelo Tosatti , Phil Auld , Paul Gortmaker , Daniel Bristot de Oliveira , Juri Lelli , Peter Zijlstra , Costa Shulyupin , Waiman Long Subject: [RFC PATCH 7/8] cgroup/cpuset: Document the new cpuset.cpus.isolation_full control file Date: Wed, 17 Jan 2024 11:35:10 -0500 Message-Id: <20240117163511.88173-8-longman@redhat.com> In-Reply-To: <20240117163511.88173-1-longman@redhat.com> References: <20240117163511.88173-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Document the new cpuset.cpus.isolation_full control file. Currently only the rcu_nocbs flag is supported, but more will be added in the future. Signed-off-by: Waiman Long --- Documentation/admin-guide/cgroup-v2.rst | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 17e6e9565156..bbd066838f93 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2352,6 +2352,30 @@ Cpuset Interface Files isolated partitions. It will be empty if no isolated partition is created. + cpuset.cpus.isolation_full + A read multiple values and write single value file which exists + on root cgroup only. + + This file shows the state of full CPU isolation mode for isolated + CPUs in isolated partitions. It shows either "0' if full CPU + isolation mode is disabled, or "1" followed by a comma-separated + list of additional CPU isolation flags that are enabled. + The currently supported CPU isolation flag is: + + rcu_nocbs + RCU no-callback CPU mode, which prevents such CPUs' + callbacks from being invoked in softirq context. + Invocation of such CPUs' RCU callbacks will instead be + offloaded to "rcuox/N" kthreads created for that purpose. + It is similar in functionality to the "rcu_nocbs" + boot command line option, but for dynamically created + isolated CPUs in isolated partitions. This flag can + only be enabled if such a "rcu_nocbs" option is present + in the boot command line of the running kernel. + + Full CPU isolation mode is enabled by writing a non-zero value + to this file and disabled by writing a zero value to it. + cpuset.cpus.partition A read-write single value file which exists on non-root cpuset-enabled cgroups. This flag is owned by the parent cgroup