From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 C3BED13CA8D for ; Mon, 2 Dec 2024 15:59:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733155174; cv=none; b=cc3PgNXEkDIpGI2pbXwXuZ6f2L3bn0ORDV9tKrdOBgCZCVySifLPZtdDdX7vliJYlefRXLG5bdYUFcP0+P2QCM27fFa7T7z5eEJyf/mb6os5Og9SOD4wBy8xY0npyGgmeK5qt+UkCVktH+1hQLVbFmjYbIDzlyIfa8ypLkPvdts= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733155174; c=relaxed/simple; bh=6+BSm5YefgojN/nFr2CcH89agNXx6NCUZ3QcJZ7fUdo=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References: Content-Type:MIME-Version; b=BUdNorArxCpOIVBn8hEv50ZMsTfJq5r9XYWuPh2RkHOxdylvlNxRxJKMnobx8ZcmBL1SH51kWTaTP7yFZySl+RZimPA7XLVi/JTIZ35MemMOS/3hIxEy9hYTedAh9sk8QDgZRw6+riZgXdiMv5ua7LE3PL+s04iHagrFa8xiphA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=X6JW9WJa; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="X6JW9WJa" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1733155171; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=6+BSm5YefgojN/nFr2CcH89agNXx6NCUZ3QcJZ7fUdo=; b=X6JW9WJa6AIWCGSMLS0eXrbGbjuAFf3XI1yQKzpcGDFl6biECAVGTVwnkfQPLgGJnJd1wF KOfBvW6yIo4uNI2iRtAerBHbtsT8M2fZfCGM0Aaaye9XMnq1mLJBMVHT6Fyu85HAkWDrV7 hXjZmXoNPkH29NHcedpx389jLCbxdWE= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-549-Xc2l8e4yON-FFQhe-8wpNQ-1; Mon, 02 Dec 2024 10:59:28 -0500 X-MC-Unique: Xc2l8e4yON-FFQhe-8wpNQ-1 X-Mimecast-MFC-AGG-ID: Xc2l8e4yON-FFQhe-8wpNQ Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-385e3cbf308so796091f8f.2 for ; Mon, 02 Dec 2024 07:59:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733155167; x=1733759967; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6+BSm5YefgojN/nFr2CcH89agNXx6NCUZ3QcJZ7fUdo=; b=gAe0bJGNuWPkBp7HrCZUfd1qtGeQCvhkBqMHjatQa2GigEB19srVN0HT0Ty1HMPEm+ 0UaziOzxBUXXT8C4YlF7YP4kDyN7c9G5DAGyuvWrj0BZmtCUCJX1yr1d7npQM3rvFrpj 6IGrShWk/9DMsjaYSBve7W3n6BRC0fWllSdN7TDmM2cA9A456JkhsvTyvH5AJshJhPjH 9B5uiAu9YZk4IF3UwHugna6FoNRYcxQ7LL/aHDsFjQIwxjTq/pXuhI05BSP5oXVGy+/S I0ulLFBFJnMIJkwkPZm++NvdiT97sy9+jYjgiQJd3nm41toRBYHkWWBHeSZTBso9cJdL B7JA== X-Forwarded-Encrypted: i=1; AJvYcCWI39jS4Bg0UQnEkKpV2srVUoKvA6fsU2bzO/Wxh6aWemNNryfLUz2Ie53ur5OkADRa7tD22gS9Sx6GtDM=@vger.kernel.org X-Gm-Message-State: AOJu0YyHR8j62tfZfHfo/XLceEbU7BvMa+Kt6phdt/5bVQLI7P7oQroA ngBMndzpEnJXDKKgz3DF6aSoSlZ3aDoFCAZAPKdOBfCQWX/6J8TTRDKr/60W98CLDFedIb8cc9h pLLRXFzVyc7RqasV2io1t5dSD0lj9h8oYMlXZJd4pWq7F9jjEwsLStAPwW+Nmpg== X-Gm-Gg: ASbGncvnSnGvFyqM5oPfsrN7abeSXGDz7po2DTqHDSCoNbSIodyPJZDNCdcKRQuOorA gyehVHV1xZxBkf7hyOxkWOoYnjoz2ZkIGU1s9i0ucjZcQtXWNeJtp6II9PBpOcv4HiewgZz9jGs KUWhqZRZ+qcfNaErycE+siAiJ9h8CSEbTYQX+3utjEYe1HfLkMywE3jqLPKRbn624UBth7jGZzz maDt9Gw1ssWLrgIdKxHpAMY3a0LE9JmXRtFDGpuOoFSUQz/tqUkESsAiHJri+3AY7Jp8NSCxuxh X-Received: by 2002:a05:6000:1567:b0:385:f7a3:fed1 with SMTP id ffacd0b85a97d-385f7a40276mr2928925f8f.44.1733155167494; Mon, 02 Dec 2024 07:59:27 -0800 (PST) X-Google-Smtp-Source: AGHT+IG8UVKO9PcvF2ItclPK8D+k/oONAjmWSeZGRBQuCT89xmSUAtYNnyZI8KKOgZ+U5/5c9KBsQQ== X-Received: by 2002:a05:6000:1567:b0:385:f7a3:fed1 with SMTP id ffacd0b85a97d-385f7a40276mr2928887f8f.44.1733155167045; Mon, 02 Dec 2024 07:59:27 -0800 (PST) Received: from gmonaco-thinkpadt14gen3.rmtit.csb ([185.107.56.42]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-434a5d56da3sm139061505e9.0.2024.12.02.07.59.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Dec 2024 07:59:26 -0800 (PST) Message-ID: <36f3b1a59604394d861ad89230a3d56231d2cae4.camel@redhat.com> Subject: Re: [PATCH 1/2] sched: Optimise task_mm_cid_work duration From: Gabriele Monaco To: Mathieu Desnoyers , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org Date: Mon, 02 Dec 2024 16:59:24 +0100 In-Reply-To: <21a18b1c-b5ae-410c-8d1f-3b63358b0e61@efficios.com> References: <20241202140735.56368-1-gmonaco@redhat.com> <20241202140735.56368-2-gmonaco@redhat.com> <6b7b30528893b091b21a06ead610709219cd9ba0.camel@redhat.com> <21a18b1c-b5ae-410c-8d1f-3b63358b0e61@efficios.com> Autocrypt: addr=gmonaco@redhat.com; prefer-encrypt=mutual; keydata=mDMEZuK5YxYJKwYBBAHaRw8BAQdAmJ3dM9Sz6/Hodu33Qrf8QH2bNeNbOikqYtxWFLVm0 1a0JEdhYnJpZWxlIE1vbmFjbyA8Z21vbmFjb0ByZWRoYXQuY29tPoiZBBMWCgBBFiEEysoR+AuB3R Zwp6j270psSVh4TfIFAmbiuWMCGwMFCQWjmoAFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcCF4AACgk Q70psSVh4TfJzZgD/TXjnqCyqaZH/Y2w+YVbvm93WX2eqBqiVZ6VEjTuGNs8A/iPrKbzdWC7AicnK xyhmqeUWOzFx5P43S1E1dhsrLWgP Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.2 (3.54.2-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2024-12-02 at 10:01 -0500, Mathieu Desnoyers wrote: >=20 > mm_cpus_allowed can be updated dynamically by setting cpu affinity > and changing the cpusets. If we change the iteration from each > possible > cpus to allowed cpus, then we need to adapt the allowed cpus updates > with the associated updates to the mm_cid as well. This is adding > complexity. >=20 > I understand that you wish to offload this task_work to a non- > isolated > CPU (non-RT). If you do so, do you really care about the duration of > task_mm_cid_work enough to justify the added complexity to the > cpu affinity/cpusets updates ? >=20 Well, no we don't really care at this point.. If it isn't a quick win I'd say I can simply remove it from the patchset, for the current use case it doesn't really matter. Thanks for the analysis. Gabriele