linux-kernel - Re: [PATCH v1] csky: use free_initmem_default() in free

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Date:   Tue, 26 Jan 2021 20:26:48 +0200
From:   Mike Rapoport <rppt@...nel.org>
To:     David Hildenbrand <david@...hat.com>
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linux-csky@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Guo Ren <guoren@...nel.org>,
        Oscar Salvador <osalvador@...e.de>,
        Michal Hocko <mhocko@...nel.org>,
        Wei Yang <richard.weiyang@...ux.alibaba.com>
Subject: Re: [PATCH v1] csky: use free_initmem_default() in free_initmem()

On Tue, Jan 26, 2021 at 07:14:20PM +0100, David Hildenbrand wrote:
> The existing code is essentially
> free_initmem_default()->free_reserved_area() without poisoning.
> 
> Note that existing code missed to update the managed page count of the
> zone.
> 
> Cc: Andrew Morton <akpm@...ux-foundation.org>
> Cc: Guo Ren <guoren@...nel.org>
> Cc: Mike Rapoport <rppt@...nel.org>
> Cc: Oscar Salvador <osalvador@...e.de>
> Cc: Michal Hocko <mhocko@...nel.org>
> Cc: Wei Yang <richard.weiyang@...ux.alibaba.com>
> Signed-off-by: David Hildenbrand <david@...hat.com>
> ---
> 
> Not compile tested as documentation on how to get
> 	https://gitlab.com/c-sky/buildroot
> running, especially with a custom kernel, is a bit sparse.

You can pick a cross-compiler from here:

https://mirrors.edge.kernel.org/pub/tools/crosstool/
 
> ---
>  arch/csky/mm/init.c | 17 +----------------
>  1 file changed, 1 insertion(+), 16 deletions(-)
> 
> diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
> index 81e4e5e78f38..894050a8ce09 100644
> --- a/arch/csky/mm/init.c
> +++ b/arch/csky/mm/init.c
> @@ -110,24 +110,9 @@ void __init mem_init(void)
>  	mem_init_print_info(NULL);
>  }
>  
> -extern char __init_begin[], __init_end[];
> -
>  void free_initmem(void)
>  {
> -	unsigned long addr;
> -
> -	addr = (unsigned long) &__init_begin;
> -
> -	while (addr < (unsigned long) &__init_end) {
> -		ClearPageReserved(virt_to_page(addr));
> -		init_page_count(virt_to_page(addr));
> -		free_page(addr);
> -		totalram_pages_inc();
> -		addr += PAGE_SIZE;
> -	}
> -
> -	pr_info("Freeing unused kernel memory: %dk freed\n",
> -	((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
> +	free_initmem_default(-1);
>  }
>  
>  void pgd_init(unsigned long *p)
> -- 
> 2.29.2
> 

-- 
Sincerely yours,
Mike.