From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4572813ACD; Tue, 16 Jan 2024 00:09:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WAFcaBw3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5FBDC433C7; Tue, 16 Jan 2024 00:09:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705363768; bh=/f1Zgeu+hdFveqlt48/Hnif/Fd8kezIBjlnUsIjQvWc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WAFcaBw31YsPeII0nWsheQolNfoqbAx+VoGMxnbCSBk8MIVyXtoro6PoRsZuNQvlg sLMuwqcXvZoENnUHvPRagUcw0WsXgRJrr58hCdOG7GcA8a4JyCvEd6x9qTnKmkBRzx +1lkwyZ34ZGn4T37gwxBxyOHVex0WpCHg8CRXTHEITf+mYN3W9sPyg1Ba+kGH7YF5C 8V1by1KPJH6CwddI16d2P78aOq2UltOIugOFHeIlDwoHdaVLJCpM8uyUmCHdDupaGi EiiFcPWXoiif9H/7hS/pZlSpTYhWjntLUI7SSKBaTcT9c9eWw0Rg9fqxCt1xz5wQnG 2XONIVF/r/jxQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vincent Guittot , Ingo Molnar , Lukasz Luba , Sasha Levin , rafael@kernel.org Subject: [PATCH AUTOSEL 6.6 6/6] energy_model: Use a fixed reference frequency Date: Mon, 15 Jan 2024 19:09:01 -0500 Message-ID: <20240116000909.212520-6-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240116000909.212520-1-sashal@kernel.org> References: <20240116000909.212520-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.12 Content-Transfer-Encoding: 8bit From: Vincent Guittot [ Upstream commit 15cbbd1d317e07b4e5c6aca5d4c5579539a82784 ] The last item of a performance domain is not always the performance point that has been used to compute CPU's capacity. This can lead to different target frequency compared with other part of the system like schedutil and would result in wrong energy estimation. A new arch_scale_freq_ref() is available to return a fixed and coherent frequency reference that can be used when computing the CPU's frequency for an level of utilization. Use this function to get this reference frequency. Energy model is never used without defining arch_scale_freq_ref() but can be compiled. Define a default arch_scale_freq_ref() returning 0 in such case. Signed-off-by: Vincent Guittot Signed-off-by: Ingo Molnar Tested-by: Lukasz Luba Reviewed-by: Lukasz Luba Link: https://lore.kernel.org/r/20231211104855.558096-5-vincent.guittot@linaro.org Signed-off-by: Sasha Levin --- include/linux/energy_model.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index b9caa01dfac4..c19e7effe764 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -224,7 +224,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util, unsigned long allowed_cpu_cap) { - unsigned long freq, scale_cpu; + unsigned long freq, ref_freq, scale_cpu; struct em_perf_state *ps; int cpu; @@ -241,11 +241,11 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, */ cpu = cpumask_first(to_cpumask(pd->cpus)); scale_cpu = arch_scale_cpu_capacity(cpu); - ps = &pd->table[pd->nr_perf_states - 1]; + ref_freq = arch_scale_freq_ref(cpu); max_util = map_util_perf(max_util); max_util = min(max_util, allowed_cpu_cap); - freq = map_util_freq(max_util, ps->frequency, scale_cpu); + freq = map_util_freq(max_util, ref_freq, scale_cpu); /* * Find the lowest performance state of the Energy Model above the -- 2.43.0