2024-04-25 07:38:31

by Vincent Guittot

Subject: [PATCH] arch/topology: Fix variable naming

Using hw_pressure for local variable is confusing in regard to the
per_cpu hw_pressure variable. Rename it to avoid confusion.

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Vincent Guittot <[email protected]>
---

drivers/base/arch_topology.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 0248912ff687..c66d070207a0 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -179,7 +179,7 @@ DEFINE_PER_CPU(unsigned long, hw_pressure);
void topology_update_hw_pressure(const struct cpumask *cpus,
unsigned long capped_freq)
{
- unsigned long max_capacity, capacity, hw_pressure;
+ unsigned long max_capacity, capacity, pressure;
u32 max_freq;
int cpu;

@@ -196,12 +196,12 @@ void topology_update_hw_pressure(const struct cpumask *cpus,
else
capacity = mult_frac(max_capacity, capped_freq, max_freq);

- hw_pressure = max_capacity - capacity;
+ pressure = max_capacity - capacity;

- trace_hw_pressure_update(cpu, hw_pressure);
+ trace_hw_pressure_update(cpu, pressure);

for_each_cpu(cpu, cpus)
- WRITE_ONCE(per_cpu(hw_pressure, cpu), hw_pressure);
+ WRITE_ONCE(per_cpu(hw_pressure, cpu), pressure);
}
EXPORT_SYMBOL_GPL(topology_update_hw_pressure);

--
2.34.1

2024-04-25 08:17:03

by Lukasz Luba

Subject: Re: [PATCH] arch/topology: Fix variable naming

On 4/25/24 08:37, Vincent Guittot wrote:
> Using hw_pressure for local variable is confusing in regard to the
> per_cpu hw_pressure variable. Rename it to avoid confusion.
>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Vincent Guittot <[email protected]>
> ---
>
> drivers/base/arch_topology.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
> index 0248912ff687..c66d070207a0 100644
> --- a/drivers/base/arch_topology.c
> +++ b/drivers/base/arch_topology.c
> @@ -179,7 +179,7 @@ DEFINE_PER_CPU(unsigned long, hw_pressure);
> void topology_update_hw_pressure(const struct cpumask *cpus,
> unsigned long capped_freq)
> {
> - unsigned long max_capacity, capacity, hw_pressure;
> + unsigned long max_capacity, capacity, pressure;
> u32 max_freq;
> int cpu;
>
> @@ -196,12 +196,12 @@ void topology_update_hw_pressure(const struct cpumask *cpus,
> else
> capacity = mult_frac(max_capacity, capped_freq, max_freq);
>
> - hw_pressure = max_capacity - capacity;
> + pressure = max_capacity - capacity;
>
> - trace_hw_pressure_update(cpu, hw_pressure);
> + trace_hw_pressure_update(cpu, pressure);
>
> for_each_cpu(cpu, cpus)
> - WRITE_ONCE(per_cpu(hw_pressure, cpu), hw_pressure);
> + WRITE_ONCE(per_cpu(hw_pressure, cpu), pressure);
> }
> EXPORT_SYMBOL_GPL(topology_update_hw_pressure);
>

Make sense

Reviewed-by: Lukasz Luba <[email protected]>

2024-04-25 08:47:01

by Sudeep Holla

Subject: Re: [PATCH] arch/topology: Fix variable naming

On Thu, Apr 25, 2024 at 09:37:09AM +0200, Vincent Guittot wrote:
> Using hw_pressure for local variable is confusing in regard to the
> per_cpu hw_pressure variable. Rename it to avoid confusion.
>

Acked-by: Sudeep Holla <[email protected]>

--
Regards,
Sudeep

2024-04-30 12:19:22

by Konrad Dybcio

Subject: Re: [PATCH] arch/topology: Fix variable naming

On 25.04.2024 9:37 AM, Vincent Guittot wrote:
> Using hw_pressure for local variable is confusing in regard to the
> per_cpu hw_pressure variable. Rename it to avoid confusion.

To avoid confusing the compiler :P

>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Vincent Guittot <[email protected]>
> ---

Fixes: d4dbc991714e ("sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()")
Tested-by: Konrad Dybcio <[email protected]> # QC SM8550 QRD
Reviewed-by: Konrad Dybcio <[email protected]>

Konrad

2024-05-15 08:28:15

by tip-bot2 for Alexey Makhalov

Subject: [tip: sched/urgent] arch/topology: Fix variable naming to avoid shadowing

The following commit has been merged into the sched/urgent branch of tip:

Commit-ID: e5bc44e47c531860be96ac615314b1ab23d5aa2b
Gitweb: https://git.kernel.org/tip/e5bc44e47c531860be96ac615314b1ab23d5aa2b
Author: Vincent Guittot <[email protected]>
AuthorDate: Thu, 25 Apr 2024 09:37:09 +02:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Wed, 15 May 2024 10:22:16 +02:00

arch/topology: Fix variable naming to avoid shadowing

Using 'hw_pressure' for local variable name is confusing in regard to the
per-CPU 'hw_pressure' variable that uses the same name:

include/linux/arch_topology.h:DECLARE_PER_CPU(unsigned long, hw_pressure);

.. which puts it into a global scope for all code that includes
<linux/topology.h>, shadowing the local variable.

Rename it to avoid compiler confusion & Sparse warnings.

[ mingo: Expanded the changelog. ]

Reported-by: kernel test robot <[email protected]>
Signed-off-by: Vincent Guittot <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Lukasz Luba <[email protected]>
Reviewed-by: Konrad Dybcio <[email protected]>
Acked-by: Sudeep Holla <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Fixes: d4dbc991714e ("sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()")
Tested-by: Konrad Dybcio <[email protected]> # QC SM8550 QRD
---
drivers/base/arch_topology.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 0248912..c66d070 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -179,7 +179,7 @@ DEFINE_PER_CPU(unsigned long, hw_pressure);
void topology_update_hw_pressure(const struct cpumask *cpus,
unsigned long capped_freq)
{
- unsigned long max_capacity, capacity, hw_pressure;
+ unsigned long max_capacity, capacity, pressure;
u32 max_freq;
int cpu;

@@ -196,12 +196,12 @@ void topology_update_hw_pressure(const struct cpumask *cpus,
else
capacity = mult_frac(max_capacity, capped_freq, max_freq);

- hw_pressure = max_capacity - capacity;
+ pressure = max_capacity - capacity;

- trace_hw_pressure_update(cpu, hw_pressure);
+ trace_hw_pressure_update(cpu, pressure);

for_each_cpu(cpu, cpus)
- WRITE_ONCE(per_cpu(hw_pressure, cpu), hw_pressure);
+ WRITE_ONCE(per_cpu(hw_pressure, cpu), pressure);
}
EXPORT_SYMBOL_GPL(topology_update_hw_pressure);