From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-104.mta0.migadu.com [91.218.175.104]) (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 D66CF1EB5CE for ; Tue, 22 Sep 2026 09:21:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.104 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790068865; cv=none; b=TMEjjNk5aJR5idLWPthYFv9o0LZbjdvV14E+PWrejDKjC7QvDeT0vGMjQ8ek3512DkLRWcuyGt0AeQCMtrJdmg++5RLFg3kPvLrScuvXrZZC/sCZwv3tfm8d2Hxs02zbeby2lxReTTsblLAXAWpUSFtCwQ7Ni4KSbG5Mey6uF/U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790068865; c=relaxed/simple; bh=pauak53psAXKLYl2w6xPdGBF4uRbBTPOApr/KH0j4F0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gPUk3Ji/m+KqcCi2Y7dtMuTYSTpBiOnFQ/R+EgmBl2I8Hfh6OcJ5BPLgCmWLOV4DBpv5529xANLvCqvOJIbxMO8VBnZOR5SuUr/2kY/S8M2Ct8wAZyUgSJtI6fs6iG9xM0DB0eaeWrSqGvNLY0lmFkRRVCijj9lIOuZolDR0ibM= 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=RaDRknwA; arc=none smtp.client-ip=91.218.175.104 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="RaDRknwA" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=pauak53psAXKLYl2w6xPdGBF4uRbBTPOApr/KH0j4F0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790068861; v=1; x=1790673661; b=RaDRknwAR3q1F1nXi0TrgJK9Vah6xNaq69HwgvHOcAx6MxmyWeCwqmgZvwD0hkeWQkahG5MU bjqjUfORI23+BJ/IEOTM2g0t1gJuYTf6cxIabozQeJFxFP3uXr9X5NUSSul0epUBdAGieHxGWsR IpXkKx7k0rbLiW7rwatlsS78= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 736ce81edee2f5a2; Tue, 22 Sep 2026 09:21:00 +0000 X-Mizu-Trace-ID: 736ce81edee2f5a2 X-Migadu-Flow: FLOW_OUT From: Guopeng Zhang To: Waiman Long , Ridong Chen Cc: Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Jonathan Corbet , Shuah Khan , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Guopeng Zhang Subject: [PATCH v3 1/2] docs: cgroup-v2: Describe boot-isolated CPUs in cpuset.cpus.isolated Date: Tue, 22 Sep 2026 17:20:33 +0800 Message-ID: <20260922092034.68840-2-guopeng.zhang@linux.dev> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260922092034.68840-1-guopeng.zhang@linux.dev> References: <20260922092034.68840-1-guopeng.zhang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@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. Suggested-by: Ridong Chen Reviewed-by: Ridong Chen Signed-off-by: Guopeng Zhang --- Documentation/admin-guide/cgroup-v2.rst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 2ec582985b5b..18a01ce4c334 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2626,8 +2626,9 @@ Cpuset Interface Files 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. + isolated partitions or isolated at boot time via the "domain" + flag of "isolcpus". The latter remain listed even after any + partition using them is released. cpuset.cpus.partition A read-write single value file which exists on non-root -- 2.43.0