Re: [RFC PATCH v1 22/33] mm/SPARC: use common help functions tofree reserved pages

[Sam Ravnborg]

On Tue, Mar 05, 2013 at 10:55:05PM +0800, Jiang Liu wrote:
> Use common help functions to free reserved pages.

I like how this simplify things!

Please consider how you can also cover the HIGHMEM case,
so map_high_region(...) is simplified too (in init_32.c).

> 
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> ---
>  arch/sparc/kernel/leon_smp.c |   15 +++------------
>  arch/sparc/mm/init_32.c      |   40 ++++++----------------------------------
>  arch/sparc/mm/init_64.c      |   25 ++++---------------------
>  3 files changed, 13 insertions(+), 67 deletions(-)
> 
> diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
> index 48e0c03..2a7b6eb 100644
> --- a/arch/sparc/mm/init_32.c
> +++ b/arch/sparc/mm/init_32.c
> @@ -374,45 +374,17 @@ void __init mem_init(void)
>  
>  void free_initmem (void)
>  {
> -	unsigned long addr;
> -	unsigned long freed;
> -
> -	addr = (unsigned long)(&__init_begin);
> -	freed = (unsigned long)(&__init_end) - addr;
> -	for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
> -		struct page *p;
> -
> -		memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
> -		p = virt_to_page(addr);
> -
> -		ClearPageReserved(p);
> -		init_page_count(p);
> -		__free_page(p);
> -		totalram_pages++;
> -		num_physpages++;
> -	}
> -	printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
> -		freed >> 10);
> +	num_physpages += free_reserved_area((unsigned long)(&__init_begin),
> +					    (unsigned long)(&__init_end),
> +					    POISON_FREE_INITMEM,
> +					    "unused kernel");
If you change free_initmem_default(...) to return number of pages freed this
could have been used here.

>  }
>  
>  #ifdef CONFIG_BLK_DEV_INITRD
>  void free_initrd_mem(unsigned long start, unsigned long end)
>  {
> -	if (start < end)
> -		printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
> -			(end - start) >> 10);
> -	for (; start < end; start += PAGE_SIZE) {
> -		struct page *p;
> -
> -		memset((void *)start, POISON_FREE_INITMEM, PAGE_SIZE);
> -		p = virt_to_page(start);
> -
> -		ClearPageReserved(p);
> -		init_page_count(p);
> -		__free_page(p);
> -		totalram_pages++;
> -		num_physpages++;
> -	}
> +	num_physpages += free_reserved_area(start, end, POISON_FREE_INITMEM,
> +					    "initrd");
>  }
>  #endif
>  
> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
> index 1588d33..03bfd10 100644
> --- a/arch/sparc/mm/init_64.c
> +++ b/arch/sparc/mm/init_64.c
> @@ -2060,8 +2060,7 @@ void __init mem_init(void)
>  	/* We subtract one to account for the mem_map_zero page
>  	 * allocated below.
>  	 */
> -	totalram_pages -= 1;
> -	num_physpages = totalram_pages;
> +	num_physpages = totalram_pages - 1;
>  
>  	/*
>  	 * Set up the zero page, mark it reserved, so that page count
> @@ -2072,7 +2071,7 @@ void __init mem_init(void)
>  		prom_printf("paging_init: Cannot alloc zero page.\n");
>  		prom_halt();
>  	}
> -	SetPageReserved(mem_map_zero);
> +	mark_page_reserved(mem_map_zero);
>  
>  	codepages = (((unsigned long) _etext) - ((unsigned long) _start));
>  	codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
> @@ -2112,7 +2111,6 @@ void free_initmem(void)
>  	initend = (unsigned long)(__init_end) & PAGE_MASK;
>  	for (; addr < initend; addr += PAGE_SIZE) {
>  		unsigned long page;
> -		struct page *p;
>  
>  		page = (addr +
>  			((unsigned long) __va(kern_base)) -
> @@ -2120,13 +2118,8 @@ void free_initmem(void)
>  		memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
>  
>  		if (do_free) {
> -			p = virt_to_page(page);
> -
> -			ClearPageReserved(p);
> -			init_page_count(p);
> -			__free_page(p);
> +			free_reserved_page(virt_to_page(page));
>  			num_physpages++;
> -			totalram_pages++;
>  		}
>  	}
>  }
> @@ -2134,17 +2127,7 @@ void free_initmem(void)
>  #ifdef CONFIG_BLK_DEV_INITRD
>  void free_initrd_mem(unsigned long start, unsigned long end)
>  {
> -	if (start < end)
> -		printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
> -	for (; start < end; start += PAGE_SIZE) {
> -		struct page *p = virt_to_page(start);
> -
> -		ClearPageReserved(p);
> -		init_page_count(p);
> -		__free_page(p);
> -		num_physpages++;
> -		totalram_pages++;
> -	}
> +	num_physpages += free_reserved_area(start, end, 0, "initrd");

Please add poison POISON_FREE_INITMEM here. I know this was not done before.

	Sam
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