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Thu, 10 Sep 2026 05:00:32 -0700 (PDT) From: Kayra Cizmeci To: jackzxcui1989@163.com Cc: bsegall@google.com, dietmar.eggemann@arm.com, juri.lelli@redhat.com, kprateek.nayak@amd.com, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org, vincent.guittot@linaro.org, vschneid@redhat.com Subject: Re: [RFC PATCH RESEND 05/10] sched/fair: Introduce select_task_rq_fair_thin() to select rq when LB_PROMOTE Date: Thu, 10 Sep 2026 15:00:29 +0300 Message-ID: <20260910120029.1207437-1-kayracizmeci@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260910042950.1619727-6-jackzxcui1989@163.com> References: <20260910042950.1619727-6-jackzxcui1989@163.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hello Xin, > Testing has shown that in our system with 18 CPUs running at 2.1GHz, where > the first three sd_llc domains each contains 4 CPUs and the last sd_llc > contains 2 CPUs, under same fillback scenario, select_task_rq_fair_thin() > executes 25% faster than the original select_task_rq_fair(). It saves 22ms > over a 10-second period, with this optimization accounting for 0.174% of > total system time. Additionally, we measured the execution time of > update_idle_cpu_scan, which took 0.5ms over the same 10-second period. If > we use select_task_rq_fair_thin() instead, this time can be eliminated, > accounting for 0.04% of total system time. Therefore, the overall > optimization contributes to a reduction of 0.214% of total system time. Okay. Can you specify which tests you ran or what you used? If you can? Thanks, Kayra