From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-67.mta0.migadu.com [91.218.175.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D6373812ED for ; Fri, 18 Sep 2026 10:24:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.67 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789727066; cv=none; b=GcXnpPQ7FzIddwa8AvJyX26uzqFmAdGZYaVZOGVKgNvPIvQZOd7eplo97XeWOVSQdQ03p5L1T8tAgiirqEfdGyzOiP1R6k5UgAYDbfEEGD4vKe+OzztVmL3DFBQR+Yn3qJ9zjhmjcUb71unJhzjh0G7yqGphHCxVHHmyKqAVjTY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789727066; c=relaxed/simple; bh=8oDsVyqBLxEiDren+mvzSBEhfATjLL22N1BKky2enWM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fYRZP5aeKydpLmtxATwPMpW1K/KZCQF43VkXHXXojCrvcTZ/4J07cUMMcraBvKUON1H2tSgIUSaDuACNx35eAgv52r6FbXa8KxHAR0XCSEKs8+xBlvwig5HAwrahXb+7gG9S7SpnvszrYbzRyHVMAm8M1/wA2UEdCnzHrDUfo3A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=LBZcRZGo; arc=none smtp.client-ip=91.218.175.67 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="LBZcRZGo" X-Envelope-To: cgroups@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=8oDsVyqBLxEiDren+mvzSBEhfATjLL22N1BKky2enWM=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789727063; v=1; x=1790331863; b=LBZcRZGogK+s/sDHopOcmI1V79FawoL1b0hvSL7ipsgtIKmzmoQiAbiYlxVWOzu9tL2ubUzF Kt/y+Pu7e1+rgh9l7dgsaSWwdR/aejacbhin5Rzo1oQ1GB7O3eY+0BaMLLSyk7/HojA+hgnwj/t Qyx6S4LOhenuho3mjLPzjU+o= X-Envelope-To: cgroups@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 49790fc8767d1b32; Fri, 18 Sep 2026 10:24:23 +0000 X-Mizu-Trace-ID: 49790fc8767d1b32 X-Migadu-Flow: FLOW_OUT From: Guopeng Zhang To: Tejun Heo , Waiman Long Cc: Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Ridong Chen , Jonathan Corbet , Shuah Khan , Randy Dunlap , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Guopeng Zhang Subject: [PATCH 1/2] docs: cgroup-v2: Describe boot-isolated CPUs in cpuset.cpus.isolated Date: Fri, 18 Sep 2026 18:23:58 +0800 Message-ID: <20260918102359.71826-2-guopeng.zhang@linux.dev> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260918102359.71826-1-guopeng.zhang@linux.dev> References: <20260918102359.71826-1-guopeng.zhang@linux.dev> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Guopeng Zhang cpuset.cpus.isolated is documented as empty when no isolated partition exists. This is not true when CPUs are isolated at boot with isolcpus=domain. cpuset_init() adds those CPUs to the isolated mask, and isolcpus= uses domain isolation by default. They remain listed after a partition using them is released. Document the boot-isolated CPUs as well. Signed-off-by: Guopeng Zhang --- Documentation/admin-guide/cgroup-v2.rst | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 2ec582985b5b..272e9f2432bd 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2625,9 +2625,11 @@ Cpuset Interface Files cpuset.cpus.isolated A read-only and root cgroup only multiple values file. - This file shows the set of all isolated CPUs used in existing - isolated partitions. It will be empty if no isolated partition - is created. + This file shows CPUs isolated from scheduler domains by + isolated cpuset partitions or at boot with "isolcpus=domain" + (including the default "isolcpus=" form). CPUs + isolated at boot remain listed after any partition using them + is released. cpuset.cpus.partition A read-write single value file which exists on non-root -- 2.43.0