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([138.199.21.246]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-c8bc3172827sm11544089a12.9.2026.06.23.23.34.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jun 2026 23:34:09 -0700 (PDT) From: Jing Wu To: Waiman Long Cc: Jing Wu , Thomas Gleixner , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, cgroups@vger.kernel.org, Qiliang Yuan Subject: Re: [PATCH-next 00/23] cgroup/cpuset: Enable runtime update of nohz_full and managed_irq CPUs Date: Wed, 24 Jun 2026 14:34:04 +0800 Message-ID: <20260624063404.2106807-1-realwujing@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260421030351.281436-1-longman@redhat.com> References: <20260421030351.281436-1-longman@redhat.com> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Waiman, Thomas Gleixner suggested we coordinate, so reaching out directly. We have been working on a similar feature called Dynamic Housekeeping Management (DHM) [1][2][3][4]. The RFC was posted on 2026-02-06, v1 on 2026-03-25, and v2 on 2026-04-13 — a week before your series appeared. It seems we developed these independently in parallel. After Thomas's review of DHM v3, we are rebuilding v4 around the CPU-by-CPU offline/online hotplug mechanism, which aligns with the direction of your series. There is one key difference in scope worth discussing: Your series requires "nohz_full=" to be present at boot (even with an empty CPU list) to opt into runtime updates. DHM targets systems where nohz_full= was never configured at boot — enabling CPU noise isolation purely at runtime without any boot-time setup. This requires making the nohz_full infrastructure activatable at runtime for the first time, rather than just extending an already- initialized boot configuration. Before we start coding v4, a few questions: 1. Are you planning a v2 of your series? If so, what is your timeline? We want to avoid duplicating effort on the subsystem patches (tick, RCU, genirq). 2. Would you be open to extending your series to cover the "no boot parameter" use case, or do you think it is better kept as a separate series? 3. Are there specific patches in your series where you would welcome our contribution directly? Happy to collaborate on a unified approach. [1] DHM RFC (2026-02-06): https://lore.kernel.org/r/20260206-feature-dynamic_isolcpus_dhei-v1-0-00a711eb0c74@gmail.com [2] DHM v1 (2026-03-25): https://lore.kernel.org/r/20260325-dhei-v12-final-v1-0-919cca23cadf@gmail.com [3] DHM v2 (2026-04-13): https://lore.kernel.org/r/20260413-wujing-dhm-v2-0-06df21caba5d@gmail.com [4] DHM v3 (2026-06-18): https://lore.kernel.org/r/20260618-wujing-dhm-v3-0-28f1a4d83b68@gmail.com [5] Your series v1 (2026-04-20): https://lore.kernel.org/r/20260421030351.281436-1-longman@redhat.com Jing Wu Qiliang Yuan