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From: Lukasz Luba <lukasz.luba@arm.com>
To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-arm-msm@vger.kernel.org, steev@kali.org,
	lukasz.luba@arm.com, sudeep.holla@arm.com, will@kernel.org,
	catalin.marinas@arm.com, linux@armlinux.org.uk,
	gregkh@linuxfoundation.org, rafael@kernel.org,
	viresh.kumar@linaro.org, amitk@kernel.org,
	daniel.lezcano@linaro.org, amit.kachhap@gmail.com,
	thara.gopinath@linaro.org, bjorn.andersson@linaro.org,
	agross@kernel.org
Subject: [PATCH v4 3/5] cpufreq: qcom-cpufreq-hw: Update offline CPUs per-cpu thermal pressure
Date: Tue,  9 Nov 2021 19:57:12 +0000	[thread overview]
Message-ID: <20211109195714.7750-4-lukasz.luba@arm.com> (raw)
In-Reply-To: <20211109195714.7750-1-lukasz.luba@arm.com>

The thermal pressure signal gives information to the scheduler about
reduced CPU capacity due to thermal. It is based on a value stored in
a per-cpu 'thermal_pressure' variable. The online CPUs will get the
new value there, while the offline won't. Unfortunately, when the CPU
is back online, the value read from per-cpu variable might be wrong
(stale data).  This might affect the scheduler decisions, since it
sees the CPU capacity differently than what is actually available.

Fix it by making sure that all online+offline CPUs would get the
proper value in their per-cpu variable when there is throttling
or throttling is removed.

Fixes: 275157b367f479 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index a2be0df7e174..0138b2ec406d 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -304,7 +304,8 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
 	if (capacity > max_capacity)
 		capacity = max_capacity;
 
-	arch_set_thermal_pressure(policy->cpus, max_capacity - capacity);
+	arch_set_thermal_pressure(policy->related_cpus,
+				  max_capacity - capacity);
 
 	/*
 	 * In the unlikely case policy is unregistered do not enable
-- 
2.17.1


WARNING: multiple messages have this Message-ID (diff)
From: Lukasz Luba <lukasz.luba@arm.com>
To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-arm-msm@vger.kernel.org, steev@kali.org,
	lukasz.luba@arm.com, sudeep.holla@arm.com, will@kernel.org,
	catalin.marinas@arm.com, linux@armlinux.org.uk,
	gregkh@linuxfoundation.org, rafael@kernel.org,
	viresh.kumar@linaro.org, amitk@kernel.org,
	daniel.lezcano@linaro.org, amit.kachhap@gmail.com,
	thara.gopinath@linaro.org, bjorn.andersson@linaro.org,
	agross@kernel.org
Subject: [PATCH v4 3/5] cpufreq: qcom-cpufreq-hw: Update offline CPUs per-cpu thermal pressure
Date: Tue,  9 Nov 2021 19:57:12 +0000	[thread overview]
Message-ID: <20211109195714.7750-4-lukasz.luba@arm.com> (raw)
In-Reply-To: <20211109195714.7750-1-lukasz.luba@arm.com>

The thermal pressure signal gives information to the scheduler about
reduced CPU capacity due to thermal. It is based on a value stored in
a per-cpu 'thermal_pressure' variable. The online CPUs will get the
new value there, while the offline won't. Unfortunately, when the CPU
is back online, the value read from per-cpu variable might be wrong
(stale data).  This might affect the scheduler decisions, since it
sees the CPU capacity differently than what is actually available.

Fix it by making sure that all online+offline CPUs would get the
proper value in their per-cpu variable when there is throttling
or throttling is removed.

Fixes: 275157b367f479 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index a2be0df7e174..0138b2ec406d 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -304,7 +304,8 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
 	if (capacity > max_capacity)
 		capacity = max_capacity;
 
-	arch_set_thermal_pressure(policy->cpus, max_capacity - capacity);
+	arch_set_thermal_pressure(policy->related_cpus,
+				  max_capacity - capacity);
 
 	/*
 	 * In the unlikely case policy is unregistered do not enable
-- 
2.17.1


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  parent reply	other threads:[~2021-11-09 19:57 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-09 19:57 [PATCH v4 0/5] Refactor thermal pressure update to avoid code duplication Lukasz Luba
2021-11-09 19:57 ` Lukasz Luba
2021-11-09 19:57 ` [PATCH v4 1/5] arch_topology: Introduce thermal pressure update function Lukasz Luba
2021-11-09 19:57   ` Lukasz Luba
2021-11-16 23:39   ` Thara Gopinath
2021-11-16 23:39     ` Thara Gopinath
2021-11-23  9:09     ` Lukasz Luba
2021-11-23  9:09       ` Lukasz Luba
2021-11-09 19:57 ` [PATCH v4 2/5] thermal: cpufreq_cooling: Use new " Lukasz Luba
2021-11-09 19:57   ` Lukasz Luba
2021-11-09 19:57 ` Lukasz Luba [this message]
2021-11-09 19:57   ` [PATCH v4 3/5] cpufreq: qcom-cpufreq-hw: Update offline CPUs per-cpu thermal pressure Lukasz Luba
2021-11-09 19:57 ` [PATCH v4 4/5] cpufreq: qcom-cpufreq-hw: Use new thermal pressure update function Lukasz Luba
2021-11-09 19:57   ` Lukasz Luba
2021-11-15 20:57   ` Thara Gopinath
2021-11-15 20:57     ` Thara Gopinath
2021-11-15 23:39     ` Thara Gopinath
2021-11-15 23:39       ` Thara Gopinath
2021-11-16  8:28       ` Lukasz Luba
2021-11-16  8:28         ` Lukasz Luba
2021-11-16  8:30     ` Lukasz Luba
2021-11-16  8:30       ` Lukasz Luba
2021-11-09 19:57 ` [PATCH v4 5/5] arch_topology: Remove unused topology_set_thermal_pressure() and related Lukasz Luba
2021-11-09 19:57   ` Lukasz Luba
2021-11-11  3:15 ` [PATCH v4 0/5] Refactor thermal pressure update to avoid code duplication Viresh Kumar
2021-11-11  3:15   ` Viresh Kumar
2021-11-23  9:11   ` Lukasz Luba
2021-11-23  9:11     ` Lukasz Luba
2021-11-23  9:45 ` Viresh Kumar
2021-11-23  9:45   ` Viresh Kumar
2021-11-23  9:46   ` Lukasz Luba
2021-11-23  9:46     ` Lukasz Luba

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