linux-kernel - [PATCH V3] PM / EM: Micro optimization in em_cpu

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Message-Id: <1606127734-14507-1-git-send-email-pkondeti@codeaurora.org>
Date:   Mon, 23 Nov 2020 16:05:32 +0530
From:   Pavankumar Kondeti <pkondeti@...eaurora.org>
To:     linux-kernel@...r.kernel.org
Cc:     Pavankumar Kondeti <pkondeti@...eaurora.org>,
        Lukasz Luba <lukasz.luba@....com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Quentin Perret <qperret@...gle.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Subject: [PATCH V3] PM / EM: Micro optimization in em_cpu_energy

When the sum of the utilization of CPUs in a performance domain is
zero, return the energy as 0 without doing any computations.

Signed-off-by: Pavankumar Kondeti <pkondeti@...eaurora.org>
---
V3: %s/power/performance as corrected by Quentin
V2: Fixed the function name in the commit message.

 include/linux/energy_model.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
index b67a51c..8810f1f 100644
--- a/include/linux/energy_model.h
+++ b/include/linux/energy_model.h
@@ -103,6 +103,9 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
 	struct em_perf_state *ps;
 	int i, cpu;
 
+	if (!sum_util)
+		return 0;
+
 	/*
 	 * In order to predict the performance state, map the utilization of
 	 * the most utilized CPU of the performance domain to a requested
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.