linux-kernel - Re: [PATCH] cpumask: de-duplicate assign

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Message-ID: <ZqvFeJVy4BpwcOjm@ghost>
Date: Thu, 1 Aug 2024 10:27:20 -0700
From: Charlie Jenkins <charlie@...osinc.com>
To: Yury Norov <yury.norov@...il.com>
Cc: linux-kernel@...r.kernel.org, Albert Ou <aou@...s.berkeley.edu>,
	Alexandre Ghiti <alexghiti@...osinc.com>,
	"Matthew Wilcox (Oracle)" <willy@...radead.org>,
	Palmer Dabbelt <palmer@...belt.com>,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Samuel Holland <samuel.holland@...ive.com>,
	Sunil V L <sunilvl@...tanamicro.com>,
	linux-riscv@...ts.infradead.org
Subject: Re: [PATCH] cpumask: de-duplicate assign_cpu() API

On Wed, Jul 31, 2024 at 12:53:54PM -0700, Yury Norov wrote:
> We've got cpumask_assign_cpu() function and assign_cpu() macro, both
> doing the same thing. We need to drop one to avoid unneeded duplicatioon.
> 
> Now that underlying assign_bit() implemented as a macro, it would make
> sense to keep assign_cpu() which is also implemented as a macro, in sake
> of unification.
> 
> This patch also removes __cpumask_assign_cpu() as the function is
> unused.
> 
> Signed-off-by: Yury Norov <yury.norov@...il.com>
> ---
>  arch/riscv/mm/cacheflush.c |  2 +-
>  include/linux/cpumask.h    | 16 ----------------
>  2 files changed, 1 insertion(+), 17 deletions(-)
> 
> diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c
> index a03c994eed3b..fa136627ccaa 100644
> --- a/arch/riscv/mm/cacheflush.c
> +++ b/arch/riscv/mm/cacheflush.c
> @@ -171,7 +171,7 @@ static void set_icache_stale_mask(void)
>  	stale_cpu = cpumask_test_cpu(smp_processor_id(), mask);
>  
>  	cpumask_setall(mask);
> -	cpumask_assign_cpu(smp_processor_id(), mask, stale_cpu);
> +	assign_cpu(smp_processor_id(), mask, stale_cpu);
>  }
>  #endif
>  
> diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
> index 801a7e524113..f896c6ffa78e 100644
> --- a/include/linux/cpumask.h
> +++ b/include/linux/cpumask.h
> @@ -534,22 +534,6 @@ static __always_inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp)
>  	__clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
>  }
>  
> -/**
> - * cpumask_assign_cpu - assign a cpu in a cpumask
> - * @cpu: cpu number (< nr_cpu_ids)
> - * @dstp: the cpumask pointer
> - * @bool: the value to assign
> - */
> -static __always_inline void cpumask_assign_cpu(int cpu, struct cpumask *dstp, bool value)
> -{
> -	assign_bit(cpumask_check(cpu), cpumask_bits(dstp), value);
> -}
> -
> -static __always_inline void __cpumask_assign_cpu(int cpu, struct cpumask *dstp, bool value)
> -{
> -	__assign_bit(cpumask_check(cpu), cpumask_bits(dstp), value);
> -}

This deletion is the wrong way around. cpumask_assign_cpu already
existed when assign_cpu was added. cpumask_assign_cpu uses the same
naming convention as all of the other cpumask functions, so it is
inconsistent with the other defines in this file to drop the "cpumask"
prefix.

__cpumask_assign_cpu is not currently used but all of the other cpumask
functions have a "__" alternative so that's why I added it.

- Charlie

> -
>  /**
>   * cpumask_test_cpu - test for a cpu in a cpumask
>   * @cpu: cpu number (< nr_cpu_ids)
> -- 

> 2.43.0
>