linux-kernel - Re: [PATCH v4 0/5] Refactor thermal pressure update to avoid code duplication

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Message-ID: <20211123094515.yeqlqsx6acj4sw7t@vireshk-i7>
Date:   Tue, 23 Nov 2021 15:15:15 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Lukasz Luba <lukasz.luba@....com>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-arm-msm@...r.kernel.org, steev@...i.org,
        sudeep.holla@....com, will@...nel.org, catalin.marinas@....com,
        linux@...linux.org.uk, gregkh@...uxfoundation.org,
        rafael@...nel.org, amitk@...nel.org, daniel.lezcano@...aro.org,
        amit.kachhap@...il.com, thara.gopinath@...aro.org,
        bjorn.andersson@...aro.org, agross@...nel.org
Subject: Re: [PATCH v4 0/5] Refactor thermal pressure update to avoid code
 duplication

On 09-11-21, 19:57, Lukasz Luba wrote:
> Hi all,
> 
> This patch set v4 aims to refactor the thermal pressure update
> code. There are already two clients which do similar thing:
> convert the capped frequency value into the capacity of
> affected CPU and call the 'set' function to store the 
> reduced capacity into the per-cpu variable.
> There might be more than two of these users. In near future
> it will be scmi-cpufreq driver, which receives notification
> from FW about reduced frequency due to thermal. Other vendors
> might follow. Let's avoid code duplication and potential
> conversion bugs. Move the conversion code into the arch_topology.c
> where the capacity calculation setup code and thermal pressure sit.
> 
> Apart from that $subject patches, there is one patch (3/5) which fixes
> issue in qcom-cpufreq-hw.c when the thermal pressure is not 
> updated for offline CPUs. It's similar fix that has been merged
> recently for cpufreq_cooling.c:
> 2ad8ccc17d1e4270cf65a3f2
> 
> The patch 4/5 fixes also qcom-cpufreq-hw.c driver code which did
> the translation from frequency to capacity wrongly when there
> was a boost frequency available and stored in 'policy->cpuinfo.max_freq'.
> 
> Changes:
> v4:
> - remove the warning when boost frequency is passed and set thermal
>   pressure to 0 in that case, which means the capping is totally removed
>   (issue reported by Steev)
> - remove the check from patch 4/5 with
>   'throttled_freq > policy->cpuinfo.max_freq' since it doesn't have
>   effect; instead relay on new arch_update_thermal_pressure() handling
>   correctly such use case; this would also fix an issue in that original
>   driver code, where the reduced capacity was calculated wrongly due
>   to 'policy->cpuinfo.max_freq' used as a divider
> - adjusted comments stressing the fact that the boost frequencies are
>   supported

> Lukasz Luba (5):
>   arch_topology: Introduce thermal pressure update function
>   thermal: cpufreq_cooling: Use new thermal pressure update function
>   cpufreq: qcom-cpufreq-hw: Update offline CPUs per-cpu thermal pressure
>   cpufreq: qcom-cpufreq-hw: Use new thermal pressure update function
>   arch_topology: Remove unused topology_set_thermal_pressure() and
>     related
> 
>  arch/arm/include/asm/topology.h   |  2 +-
>  arch/arm64/include/asm/topology.h |  2 +-
>  drivers/base/arch_topology.c      | 42 ++++++++++++++++++++++++++++---
>  drivers/cpufreq/qcom-cpufreq-hw.c | 14 +++--------
>  drivers/thermal/cpufreq_cooling.c |  6 +----
>  include/linux/arch_topology.h     |  4 +--
>  include/linux/sched/topology.h    |  6 ++---
>  init/Kconfig                      |  2 +-
>  8 files changed, 50 insertions(+), 28 deletions(-)

Applied. Thanks.

-- 
viresh