From mboxrd@z Thu Jan 1 00:00:00 1970 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 3A06A350A02 for ; Mon, 12 Jan 2026 18:23:59 +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=1768242241; cv=none; b=iTptsNHitjdRPTK4Kq64oGnbHqm2fUcjD3l8NKL8CagCOQgzEkjn0grt46Gdv8H2uHgXZ1iVSXGywPCNUKcsF24Q5Ec4dfeaVgfda1UtJCScKUBLTx5Oe+9Y+tGc5svdRmu+I46BtHoLZMo/2wuIL3MeXVwNWGZ3vVj14j4eICA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768242241; c=relaxed/simple; bh=zpoNdTeaB4i3QK4pd6pXO1rrYW3DhRqSBMGvDT0il6g=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=Q6gye1TkwkSF/CDOqAFVC8OBWvNVlGRviHFvBwn90kHSCf7/o/EdNtJlZYu2pjxrHgwWuPSw5SwybSQ2j/uPw+bYrmiUmYHGK0xTRvGx5wzxwYuFYC7wJv8T+FmhubYiCaRa9bBU5KWrrtjQexueC8HA7Q3K6B3v4nZ10h5cC4A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=FWpZ9Lrv; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=guWZ/pOZ; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="FWpZ9Lrv"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="guWZ/pOZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1768242239; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2gLOxIDyxhTvVzJuSwvSFZ4MlqhsCFk9OHFtuRb1ESk=; b=FWpZ9LrvYHiS7aGdljd+Igfcct2cokATR6+D5ebFep8iti98uX0GqcrakCmUdIlJh8z3o/ eHRLERNxEe9QPsW2VDqS2q5yvNLWuPgqzxtjJAewEQbRjK+OuvXSF2ATwYstzR/B+Kwmmw aHufBShApfcsR1sjFnEi4/uVfHYjqis= Received: from mail-vs1-f72.google.com (mail-vs1-f72.google.com [209.85.217.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-250-kHWSszMSNdyt2TVXDFqXHA-1; Mon, 12 Jan 2026 13:23:57 -0500 X-MC-Unique: kHWSszMSNdyt2TVXDFqXHA-1 X-Mimecast-MFC-AGG-ID: kHWSszMSNdyt2TVXDFqXHA_1768242237 Received: by mail-vs1-f72.google.com with SMTP id ada2fe7eead31-5ec9a4e6cb0so5988222137.0 for ; Mon, 12 Jan 2026 10:23:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1768242237; x=1768847037; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:from:to :cc:subject:date:message-id:reply-to; bh=2gLOxIDyxhTvVzJuSwvSFZ4MlqhsCFk9OHFtuRb1ESk=; b=guWZ/pOZLgLBpVMG05eI3nl8fDNrxtbg2JeJCnJpCJrPxAsxB0oM8wX1VZpMXoNChX pxVtL3oEQmmej+J7Eoz8v2sBGDeskbAevIn9NmTy3ojM3gvsNXW2FCX7PLS/gSwFs9Rg 22898MVltwFNGxKeyaMy5jSocMHB7lcT1a6L12IkSe0hAwRkjhrPwbyiDdX6Q6ipjmqT ACAnBfRKxgkyS7q8cV5a2zWbQWX23rvz/z6tCe1AjFaUArNLOnZJ3Ouwlsk2WJK/lbk9 hYiI6TnNwFUjKyE28XmfU3yhWW02R0ju/S/QE4BQz+4ubhR5V1itNdkLypLRsXsJi1Eg EMlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768242237; x=1768847037; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=2gLOxIDyxhTvVzJuSwvSFZ4MlqhsCFk9OHFtuRb1ESk=; b=H+F3TMKQ4xPuZ7QnrFneCWlvzR0PAlf4gfO/OC+7FtPQGXmgqaW+gZ9fTywDAYi8eD HveH6uPLbkygO3eenAwrGi6pf2uycFT2gULxdmaFegPLPFkheDyJxaCZXNkgECITrWbx kdX1CFucKyyFNsKznHJ7eO0nKUsj4AzDL1HYFtGVsyWLH4rJf6XEPi6tT3fI/bHHSwIB wl8TS1U9IAjly8rrjapHW0P2YLch+hCyBt2LLsYEqHLHAwJr/K9eyMzpZH1RYFcRiqye cr+kl4fGqtg3MLrzlPN5d+4HXNKiInlDkf7mOQkyL9vy9yhh58PZYkX+7LeUh/UE5UH/ rc0A== X-Forwarded-Encrypted: i=1; AJvYcCXFXEzmNP4/EUvlQX8kZnMxA4S7JQFQjq+e4kWNSlW6NjsZLt8rQumXvuJN2VhsM+5VErNkVf73m/Aw/Q==@vger.kernel.org X-Gm-Message-State: AOJu0YzactxNHg4D7O0drpR9cuOPJyouZmzRJ5Di0H9XaS8cgEmdj7kn EDXtJwkq6fLyOKoKrDy5noXIr55c0jUCniwxOUku4cs+XpqmkZrKemp4SFO8pHF6EtBwNthZcUf S/qQqorpOhIbGudpR6UUHR/0ri6fN6AaigKee9G9JGXdS/+USQs1LjCCPVbJ5ja6w X-Gm-Gg: AY/fxX5i2zh/yJbcUNCG39xgfpGp6ZM+soPJaEwFEc2WtZBF5m2dasbx3sqGBaIIYaY LNqC6QRaJ6rg844UUSqa95tUIRIevfmMAO0Ev98QVwJrhwl/3yI8a3wyoxaBwAdz23LxPBpOAHK sOIycwHmstNBoFhGzTPHnCXzduoHDQjfR5Ac4j4FjaTJGEVntXjBnxnd95P/owR55E4G/x8bNia KHObEXZr4sam5YcRINyVsGKdWRxSGqSxYbuujj1XgT7NtayKwOGqG9vK3hqivHACM9QUyA9Bnh8 /0am5LyW2FmZOxMzuvbDM976zbh2t3WYS2sxNDFnv/GnxTSoNwb16MKLZ68ZBrFI+QDFhMUN6cB ORifUe6eWNmwVIKi//GfcYUFma4F1z7gsny6rwjZCl0f2Tpg9zlThiWff X-Received: by 2002:a05:6102:ccd:b0:5ef:b5fc:dd4c with SMTP id ada2fe7eead31-5efb5fceabcmr2465151137.7.1768242237202; Mon, 12 Jan 2026 10:23:57 -0800 (PST) X-Google-Smtp-Source: AGHT+IFwmHNbjOkRHiOzASiFvy8qH079mvHRUgTgzybGWlZGH94huRhJ7zei/lWRFsGQLOin7Q4KDw== X-Received: by 2002:a05:6102:ccd:b0:5ef:b5fc:dd4c with SMTP id ada2fe7eead31-5efb5fceabcmr2465086137.7.1768242235294; Mon, 12 Jan 2026 10:23:55 -0800 (PST) Received: from ?IPV6:2601:188:c102:b180:1f8b:71d0:77b1:1f6e? ([2601:188:c102:b180:1f8b:71d0:77b1:1f6e]) by smtp.gmail.com with ESMTPSA id ada2fe7eead31-5ef15be79c6sm10965711137.12.2026.01.12.10.23.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Jan 2026 10:23:54 -0800 (PST) From: Waiman Long X-Google-Original-From: Waiman Long Message-ID: <437ccd7a-e839-4b40-840c-7c40d22f8166@redhat.com> Date: Mon, 12 Jan 2026 13:23:40 -0500 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 00/33 v6] cpuset/isolation: Honour kthreads preferred affinity To: Frederic Weisbecker , LKML Cc: Tejun Heo , Phil Auld , Peter Zijlstra , Lai Jiangshan , Danilo Krummrich , Catalin Marinas , Michal Koutny , netdev@vger.kernel.org, Roman Gushchin , linux-block@vger.kernel.org, Thomas Gleixner , Eric Dumazet , Michal Hocko , Bjorn Helgaas , Ingo Molnar , Chen Ridong , cgroups@vger.kernel.org, linux-pci@vger.kernel.org, Greg Kroah-Hartman , "David S . Miller" , Vlastimil Babka , Marco Crivellari , Andrew Morton , Jens Axboe , "Rafael J . Wysocki" , Johannes Weiner , Simon Horman , Shakeel Butt , linux-mm@kvack.org, Jakub Kicinski , linux-arm-kernel@lists.infradead.org, Gabriele Monaco , Muchun Song , Will Deacon , Paolo Abeni , Chen Ridong References: <20260101221359.22298-1-frederic@kernel.org> Content-Language: en-US In-Reply-To: <20260101221359.22298-1-frederic@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/1/26 5:13 PM, Frederic Weisbecker wrote: > Hi, > > The kthread code was enhanced lately to provide an infrastructure which > manages the preferred affinity of unbound kthreads (node or custom > cpumask) against housekeeping constraints and CPU hotplug events. > > One crucial missing piece is cpuset: when an isolated partition is > created, deleted, or its CPUs updated, all the unbound kthreads in the > top cpuset are affine to _all_ the non-isolated CPUs, possibly breaking > their preferred affinity along the way > > Solve this with performing the kthreads affinity update from cpuset to > the kthreads consolidated relevant code instead so that preferred > affinities are honoured. > > The dispatch of the new cpumasks to workqueues and kthreads is performed > by housekeeping, as per the nice Tejun's suggestion. > > As a welcome side effect, HK_TYPE_DOMAIN then integrates both the set > from isolcpus= and cpuset isolated partitions. Housekeeping cpumasks are > now modifyable with specific synchronization. A big step toward making > nohz_full= also mutable through cpuset in the future. > > Changes since v5: > > * Add more tags > > * Fix leaked destroy_work_on_stack() (Zhang Qiao, Waiman Long) > > * Comment schedule_drain_work() synchronization requirement (Tejun) > > * s/Revert of/Inverse of (Waiman Long) > > * Remove housekeeping_update() needless (for now) parameter (Chen Ridong) > > * Don't propagate housekeeping_update() failures beyond allocations (Waiman Long) > > * Whitespace cleanup (Waiman Long) > > > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git > kthread/core-v6 > > HEAD: 811e87ca8a0a1e54eb5f23e71896cb97436cccdc > > Happy new year, > Frederic I don't see any major issue with this v6 version. There may be some minor issues that can be cleaned up later. Now the issue is which tree should this series go to as it touches a number of different subsystems with different maintainers. Cheers, Longman