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([2a09:bac1:2880:f0::319:a]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4279f2cc32esm165310455e9.35.2024.07.16.07.16.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jul 2024 07:16:46 -0700 (PDT) From: Matt Fleming X-Google-Original-From: Matt Fleming To: yu.c.chen@intel.com Cc: aaron.lu@intel.com, dietmar.eggemann@arm.com, gautham.shenoy@amd.com, juri.lelli@redhat.com, kprateek.nayak@amd.com, linux-kernel@vger.kernel.org, mgorman@techsingularity.net, mingo@redhat.com, peterz@infradead.org, tim.c.chen@intel.com, vincent.guittot@linaro.org, yu.chen.surf@gmail.com Subject: Re: [RFC PATCH 0/7] Optimization to reduce the cost of newidle balance Date: Tue, 16 Jul 2024 15:16:45 +0100 Message-Id: <20240716141645.637620-1-mfleming@cloudflare.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > Hi, > > This is the second version of the newidle balance optimization[1]. > It aims to reduce the cost of newidle balance which is found to > occupy noticeable CPU cycles on some high-core count systems. Hi there, what's the status of this series? I'm seeing this same symptom of burning cycles in update_sd_lb_stats() on an AMD EPYC 7713 machine (128 CPUs, 8 NUMA nodes). The machine is about 50% idle and upadte_sd_lb_stats() sits as the first entry in perf top with about 3.62% of CPU cycles. Thanks, Matt