From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6EC18C433FE for ; Tue, 16 Nov 2021 00:42:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DA5D61205 for ; Tue, 16 Nov 2021 00:42:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349932AbhKPApi (ORCPT ); Mon, 15 Nov 2021 19:45:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:44648 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343827AbhKOTWJ (ORCPT ); Mon, 15 Nov 2021 14:22:09 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 70480635ED; Mon, 15 Nov 2021 18:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637002006; bh=QpGi9pmWDoQWDWTiPXW1eevR+tAtIcUVVaVpg/+oFXc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bWiVQZz8w6Ay/IDNcVEjxoSQAI+3V5oHunRgskn3peupBzi/5B0uOrR9G/z+sfLQO YQwPgGPYOBMQDi/8Mad02fCShX7CDLnlIXJcm6WFuJQwJugpTnVj1FodixYik4fSa7 HTBg3ogNWAHG2X5vkverAecQaSF6nomm4p3DBagE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vincent Donnefort , Quentin Perret , Lukasz Luba , Matthias Kaehlcke , Viresh Kumar , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.15 403/917] PM: EM: Fix inefficient states detection Date: Mon, 15 Nov 2021 17:58:18 +0100 Message-Id: <20211115165442.453254519@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165428.722074685@linuxfoundation.org> References: <20211115165428.722074685@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vincent Donnefort [ Upstream commit aa1a43262ad5df010768f69530fa179ff81651d3 ] Currently, a debug message is printed if an inefficient state is detected in the Energy Model. Unfortunately, it won't detect if the first state is inefficient or if two successive states are. Fix this behavior. Fixes: 27871f7a8a34 (PM: Introduce an Energy Model management framework) Signed-off-by: Vincent Donnefort Reviewed-by: Quentin Perret Reviewed-by: Lukasz Luba Reviewed-by: Matthias Kaehlcke Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- kernel/power/energy_model.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index a332ccd829e24..97e62469a6b32 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -107,8 +107,7 @@ static void em_debug_remove_pd(struct device *dev) {} static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, int nr_states, struct em_data_callback *cb) { - unsigned long opp_eff, prev_opp_eff = ULONG_MAX; - unsigned long power, freq, prev_freq = 0; + unsigned long power, freq, prev_freq = 0, prev_cost = ULONG_MAX; struct em_perf_state *table; int i, ret; u64 fmax; @@ -153,27 +152,21 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, table[i].power = power; table[i].frequency = prev_freq = freq; - - /* - * The hertz/watts efficiency ratio should decrease as the - * frequency grows on sane platforms. But this isn't always - * true in practice so warn the user if a higher OPP is more - * power efficient than a lower one. - */ - opp_eff = freq / power; - if (opp_eff >= prev_opp_eff) - dev_dbg(dev, "EM: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", - i, i - 1); - prev_opp_eff = opp_eff; } /* Compute the cost of each performance state. */ fmax = (u64) table[nr_states - 1].frequency; - for (i = 0; i < nr_states; i++) { + for (i = nr_states - 1; i >= 0; i--) { unsigned long power_res = em_scale_power(table[i].power); table[i].cost = div64_u64(fmax * power_res, table[i].frequency); + if (table[i].cost >= prev_cost) { + dev_dbg(dev, "EM: OPP:%lu is inefficient\n", + table[i].frequency); + } else { + prev_cost = table[i].cost; + } } pd->table = table; -- 2.33.0