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Fri, 30 Oct 2026 03:22:35 -0700 (PDT) Received: from lima-ubuntu.hz.ali.com ([47.246.98.219]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3ae845ae5b9sm3567615a91.12.2026.10.30.03.22.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Oct 2026 03:22:35 -0700 (PDT) From: Qing Wang To: peterz@infradead.org Cc: bsegall@google.com, davichazbh@gmail.com, dietmar.eggemann@arm.com, juri.lelli@redhat.com, kprateek.nayak@amd.com, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@redhat.com, rostedt@goodmis.org, tim.c.chen@linux.intel.com, vincent.guittot@linaro.org, vschneid@redhat.com, wangqing7171@gmail.com, yu.c.chen@intel.com Subject: Re: [PATCH v4] sched/fair: Replace random newidle_balance with Bresenham accumulator Date: Fri, 30 Oct 2026 18:22:26 +0800 Message-Id: <20261030102226.2501158-1-wangqing7171@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20261030095630.GJ2668200@noisy.programming.kicks-ass.net> References: <20261030095630.GJ2668200@noisy.programming.kicks-ass.net> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Fri, 30 Oct 2026 at 17:56, Peter Zijlstra wrote: > Funnily enough, treating this as an independent variable and using a > random number works and 'fixes' the slope change problems. Hi Peter, I explained this in the v3 thread: on a slope change, carrying newidle_window_pos over from the previous window only shifts the first allowed balance in the new-slope window (512 calls) earlier or later; subsequent balances are still uniformly spaced. So the initial value can be anything — it doesn't matter. -- Best regards, Qing