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 5E5F91F37D4 for ; Tue, 4 Nov 2025 03:42:11 +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=1762227732; cv=none; b=CqgRiNFJPKR8TWRYGs0RoJ1FGlWMpU2Q6MKbSlG8jNrT/N76FT9sq2HweuorFtGsMSDtRZDLzwafmXwsrgz7nxZALyISg4OL3zSIoeclLuj0XfZI/NvHaYVK/TP9FtJOmiPNY8W941ZeWEHnQaGLHl8MtWOH/so3P0sHclSSqUg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762227732; c=relaxed/simple; bh=nALavD90YtUAUwK1yEQ+Fl0sw0bKiv/LwN6AWKl1/ns=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=XkVKlAwxkDBUHWnw/S1/AVDsD6nGO6gJbm/lJL38DuUndPaEjR+Jx07Fu3wxrZH0rBAeDd0pr9t7+SPeM8qLfIGScLPtyju2UYiIkOrlWcoZF9plh+DFIg6cTRforQCznpyhZfpT7GLwnnCjGPALX2RHYAVh3acr/p67g3KU0bI= 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=FRgim8wm; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=JesOyuKC; 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="FRgim8wm"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="JesOyuKC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1762227730; 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=i9vIh1x3SmNDr7XBqfO6Je4s2k/Z++Ha6rQOUWBYrSE=; b=FRgim8wmyvbBU4omRu00pOPfmmJ2Jp+csqtcTx09XX9/NxdKf52fURjZKlYnyNGtMbGkVt Br1p7uk5DjqiIxN78RPnRdLvgAVN4j1PItPfq08w+V+si0O2dIk9HTOg24qjlK+5bl0nO4 AyAOJiZJEmf1/OUQtP+eSGZTMjscmRw= Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-116-9UqhLt5aPxap_gEOUM7exQ-1; Mon, 03 Nov 2025 22:42:08 -0500 X-MC-Unique: 9UqhLt5aPxap_gEOUM7exQ-1 X-Mimecast-MFC-AGG-ID: 9UqhLt5aPxap_gEOUM7exQ_1762227728 Received: by mail-qt1-f197.google.com with SMTP id d75a77b69052e-4ecf8faf8bdso149238501cf.1 for ; Mon, 03 Nov 2025 19:42:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1762227728; x=1762832528; 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=i9vIh1x3SmNDr7XBqfO6Je4s2k/Z++Ha6rQOUWBYrSE=; b=JesOyuKCU2P9uVY53JL9oSLwKIZGkrkhw2S2Yel7z2GdrpGwVFWJ7cMxL3He1Lz3Fw 18E86zIHN3qnjcDR2fgyZN7oeBEh/ew3OAnEk4e2oFDeiCNBRRe0Fyq1s1rsjnRHLLaO dk4J3sni0uuufghJ+0bIWpAaDE0i7CUXQXNHQ5U69op9zVImNSMFBS8dlH24wklR51TC jc6EDb5Wk7p3ezFHyFMQWtdeFTkTZ2i2Bp+uOZAV7jDb/eNB2HpGBa3jxgJz/WtIKPcE jK7ANwrsQeYCB4tBIHKknq+0X1SW8Fr2lnDydrLhhEz8eSrkD33gTeQP4kjXj6owq90s ZdPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762227728; x=1762832528; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=i9vIh1x3SmNDr7XBqfO6Je4s2k/Z++Ha6rQOUWBYrSE=; b=plntHRc86yvGqNzYQ9P1boiTCDxFOdqs5gKi9sRlxRdxtbfyHMDtJRnjlBYAOWI9ei 2+rIjlQfD6kwtF68Hq46wBYWBQ6JEUsfZg8YSaxKAcH9A90u1dqiIdzLz2GdUKyIamxB kC4OXfi+prdG6w4WabW4wlkNJITN1MPVj5kL5nl9/8atVqqcPz6DxPp8GemMumnJyrpu Mjn4GxnvDlycQqonRgkwdMhckTM2+uCHrctgFZanqvQ7NFwIZlm9940Y7McWjLTolBnV psRYyGZhxfBdqX8/0w9xcyPj0GoJUb1lYgLEjSCXu0bkG3tSgacJ8VBcM+3nSMyUtSHb Q7RA== X-Forwarded-Encrypted: i=1; AJvYcCXkDvNyQcCJqASD91GPDCdC8HV3Pxl1sxNoeIRwcbErwXI9QIWvqrx7hWkj8FTrspEtmJ/YnJ+w6GyPq5I=@vger.kernel.org X-Gm-Message-State: AOJu0Yykw5Gxq2lOLAxb5OQpokQQEskXj6LXWF5+UFzQgHoKZLjz5X06 YzSelw7l+qNt6UyQV+NAPssnZSQlVmnw1w0E4Au6hQA17m40DPuFymPrgs/jwb+fmEhAyOzpFiP dswbL+XyCmOmgbS3XrjhDLOnbTnDzic2GO2Coi3AQ9LcF1Sf2lH6h20nvtztDTezS4g== X-Gm-Gg: ASbGncsyMqTp1bvl3ceoI+kw/PT8Hox/k5V3NV3ayI1jncWBXhQ9EZAQJETg5ThCrBc VJ9VOqeG9EBL4P6ZUqWx+n+Dg/AsmJMmJOG8n/PassX44Ex0sXkdoiv9Lv4iTF+8hWWxwMhIN7U rLzhoCInGvjWB8uM9dU1CXCn63ZL1FtSYzbMH92/eOuI50Si9aaWBKvofUbClDxAL+Krau2Cf+z 09P2zQ3biNHWHp5MBHfJmTdrjtQuFyMU0SX/eI8blSQ4Jg7tX4r90f54kIc/dv/KJL399bkT0Yb zCzw4yeOARRTyIcZDxld0OZMhlsxHeD3A+qQIUCyAusItOZWx/wiYvmX4DjbyuJUE0/rzLR8TkR k9SgIhLszd8BsrwT8L66Z033W1COijjh6PtCgTgp99tf3vg== X-Received: by 2002:a05:622a:5c98:b0:4ec:f5a1:a2b9 with SMTP id d75a77b69052e-4ed30e1023cmr213821241cf.37.1762227728403; Mon, 03 Nov 2025 19:42:08 -0800 (PST) X-Google-Smtp-Source: AGHT+IHBL4mprOcyc8cXgHvQ5AlkiT/XJ4kSUe2h4HETd65StxQ+s0KyQ089NkZY32rNM+nYQ0VquA== X-Received: by 2002:a05:622a:5c98:b0:4ec:f5a1:a2b9 with SMTP id d75a77b69052e-4ed30e1023cmr213821041cf.37.1762227728091; Mon, 03 Nov 2025 19:42:08 -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 d75a77b69052e-4ed64f14f93sm3224961cf.26.2025.11.03.19.42.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 03 Nov 2025 19:42:07 -0800 (PST) From: Waiman Long X-Google-Original-From: Waiman Long Message-ID: <5d755e54-ff86-4cd0-87bf-86290d4f13de@redhat.com> Date: Mon, 3 Nov 2025 22:42:05 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv4 2/2] sched/deadline: Walk up cpuset hierarchy to decide root domain when hot-unplug To: Pingfan Liu , Juri Lelli Cc: Waiman Long , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Peter Zijlstra , Pierre Gondois , Frederic Weisbecker , Ingo Molnar , Tejun Heo , Johannes Weiner , =?UTF-8?Q?Michal_Koutn=C3=BD?= , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider References: <20251028034357.11055-1-piliu@redhat.com> <20251028034357.11055-2-piliu@redhat.com> <52252077-30cb-4a71-ba2a-1c4ecb36df37@redhat.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/3/25 10:34 PM, Pingfan Liu wrote: >> If that is the case, and assuming nobody touched the sleeping task >> affinity (p->cpus_ptr), can't we just use another online cpu from > In fact, IIUC, the change will be always propagated through the cpuset > hier into cpus_ptr by cpuset_update_tasks_cpumask() in cpuset v2. > (Ridong, please correct me if my understanding is wrong) For kthreads, changes to p->cpus_ptr via cpuset is going to be updated with a new set of kthread patch [1] being reviewed right now. [1] https://lore.kernel.org/lkml/20251013203146.10162-1-frederic@kernel.org/ Cheers, Longman