Re: [PATCH 01/24] asm-generic: add generic versions of mmu context functions

From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: Nicholas Piggin <npiggin@gmail.com>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH 01/24] asm-generic: add generic versions of mmu context functions
Date: Tue, 28 Jul 2020 04:01:24 +0000	[thread overview]
Message-ID: <12ac3789-71a5-2756-6a9e-769302c7b3c6@synopsys.com> (raw)
In-Reply-To: <20200728033405.78469-2-npiggin@gmail.com>

On 7/27/20 8:33 PM, Nicholas Piggin wrote:
> Many of these are no-ops on many architectures, so extend mmu_context.h
> to cover MMU and NOMMU, and split the NOMMU bits out to nommu_context.h
> 

> -static inline void switch_mm(struct mm_struct *prev,
> -			struct mm_struct *next,
> -			struct task_struct *tsk)
> +/**
> + * activate_mm - called after exec switches the current task to a new mm, to switch to it
> + * @prev_mm: previous mm of this task
> + * @next_mm: new mm
> + */
> +#ifndef activate_mm
> +static inline void activate_mm(struct mm_struct *prev_mm,
> +			       struct mm_struct *next_mm)
>  {
> +	switch_mm(prev_mm, next_mm, current);
>  }
> +#endif

Is activate_mm() really needed now. It seems most arches have
   activate_mm(p, n) -> switch_mm(p, n, NULL)

And if we are passing current, that can be pushed inside switch_mm()

>  
> -static inline void activate_mm(struct mm_struct *prev_mm,
> -			       struct mm_struct *next_mm)