From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.150 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794291861; b=yyTAfjn6NYGDfim28sbH5f43OgZRAbWiU+Z7eVfd16kIhFVG0mwTL7npnea7O68tKaqi kwOWRiJKmY4JXrmHjlCaqg/VlOnvLwpxLUhlHk9KW6zZfDA5p41RD+uZBkOwHow3qIrs4 LS8EjG1lNa7Ygc7sR61oQYYC6xNmQWgEGAT44KgngZx7c88JyjBQxs33oHIvKv8/MjDi9 +jp7/1LbR5VYd+bJrHZuRnC42zgULMqzPbeOaJtNribjkf3v9W7Uj0qm+CmhERRssYw8i 6vR9qUiaMTEvdIoEsMD6D6gLCHUanTFNa1aXRFddeQjG3sfXkYhQKkSFbnoSdS35WiQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794291861; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding; bh=BL+W2T/2cuMST/SB8p0zoQbSb3TF01znFaP7YILvqJQ=; b=U/9qbDGxanz5YqzK+TOJOgT3X+Oj9Dh9jyp0bM7/IWUg6m5uWK//TPakszhNtRnUysWQ ToWYeJ8w2/ofWohVot0mPGWVNL+waSU93Jvos7bY8IoGntU2uqQtkhx5lZCcyLip1JIc/ pWxq7vezx2kyCLVG4i7k23b2qTNjl9TfP0/pmDMvnxOhrIDG89jAQYnqcTlYYhdxTNqRP Hrq6QGycWoHrPM6RFZbMt4xJyG9DGlnkbvP3n9/BkJhSU6ejDqfanB/cBKAr0e/tCVyop MH2dKUQLALBrXwEcNOvAl84VAkUryb6++qmFIdSYTVZpUiqkUSWbXL/6xPl1op6W7Jg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=u7Ozoluy; arc=none smtp.remote-ip=91.218.175.150 Received: from mta0.migadu.com (out-150.mta0.migadu.com [91.218.175.150]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F30E3606A31C for ; Tue, 10 Nov 2026 06:24:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org F30E3606A31C 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, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=u7Ozoluy X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=7ght3jiINuFCMHMQNMsTCNCFy1DQnY7GC46bKdA/Shk=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794291855; v=1; x=1794896655; b=u7OzoluyaEZu/1fB41vNlYs5mPIqZG1ptnG6WIv3AEo6L3+dk6Da+n/w3jZE5PLCZXFEv+Kk Sv2d+NgBbKEGka+cYl5zIBinDqYPZqu8zH5FmTssDGa0X/WGxKGO0/8z79hJhy3Bn8gk7Bs5GcH FW0U/UlTP8VqE2Ps92rE9whs= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 9578d8396b621a0b; Tue, 10 Nov 2026 06:24:15 +0000 X-Mizu-Trace-ID: 9578d8396b621a0b X-Migadu-Flow: FLOW_OUT Message-ID: Date: Tue, 10 Nov 2026 14:24:07 +0800 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 3/4] cpuset: settle isolation state when CPUs are given back to parent To: Guopeng Zhang , Waiman Long , Tejun Heo , Johannes Weiner , =?UTF-8?Q?Michal_Koutn=C3=BD?= , Shuah Khan Cc: Chen Ridong , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Sashiko , Guopeng Zhang , Ridong Chen References: <20261107120100.3587595-1-ridong.chen@linux.dev> <20261107120100.3587595-4-ridong.chen@linux.dev> From: Ridong Chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 11/9/2026 11:20 PM, Guopeng Zhang wrote: > > > 在 2026/11/7 20:00, Ridong Chen 写道: >> From: Ridong Chen >> >> partition_xcpus_del() only updates isolated_cpus when the partition that >> gives back the CPUs has a different state than its parent. CPUs that were >> further distributed to descendant isolated partitions are not taken into >> account, so isolated_cpus_release() has to be called afterwards in >> several places to walk up the ancestors and fix isolated_cpus. >> >> Make partition_xcpus_del() always set the isolation state of the given >> back CPUs to the state of the parent that receives them. As the >> effective_xcpus of a partition covers the CPUs distributed to its >> descendants, the isolation state of those CPUs is settled at the same >> time. Boot-time isolated CPUs are still preserved by isolated_cpu_update(). >> >> compute_partition_effective_cpumask() invalidates a child partition >> without going through partition_xcpus_del(), so do the same there: the >> CPUs of the invalidated child take the isolation state of its parent. >> >> As the parent may be shrunk and its effective_xcpus not updated yet, >> only do so for the CPUs the parent still owns. This is to keep the >> isolation state correct for now, the in-place invalidation here will be >> removed later in the partition rework. >> >> isolated_cpus_update() assumes the old and new states are different, >> which no longer holds now that partition_xcpus_del() proceeds regardless >> of the states. Drop its @old_prs argument and the WARN_ON_ONCE() so that >> it simply sets the isolation state of the given CPUs, and use it >> everywhere. The state check in partition_xcpus_add() is dropped as well, >> as setting the state is a no-op when the states are the same. >> >> isolated_cpus_release() is no longer needed and is removed. >> > > Hi Ridong, > > Would it be worth briefly mentioning in the commit message that this patch also fixes the issue described here? > > https://lore.kernel.org/all/20261105130344.664336-4-guopeng.zhang@linux.dev/ > Thanks, Guopeng. As I replied to Longman, I will add it. -- Best regards Ridong