[precise][PATCH 1/2](upstream) mm: introduce helper function mem_init_print_info() to simplify mem_init()

[Tim Gardner]

On 09/12/2016 07:01 PM, Dan Streetman wrote:
> From: Jiang Liu <liuj97 at gmail.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1622567
> 
> Backport required only context changes.  Only part of this is required
> by the next patch, the get_num_physpages() function.  This patch does
> contain the other part of the upstream commit, the mem_init_print_info()
> function, although the next patch in this series does not require it.
> 
> Introduce helper function mem_init_print_info() to simplify mem_init()
> across different architectures, which also unifies the format and
> information printed.
> 
> Function mem_init_print_info() calculates memory statistics information
> without walking each page, so it should be a little faster on some
> architectures.
> 
> Also introduce another helper get_num_physpages() to kill the global
> variable num_physpages.
> 
> Signed-off-by: Jiang Liu <jiang.liu at huawei.com>
> Cc: Mel Gorman <mgorman at suse.de>
> Cc: Michel Lespinasse <walken at google.com>
> Cc: Rik van Riel <riel at redhat.com>
> Cc: Minchan Kim <minchan at kernel.org>
> Cc: Marek Szyprowski <m.szyprowski at samsung.com>
> Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
> (backported from commit 7ee3d4e8cd560500192d80ca84d7f15d6dee0807 upstream)
> Signed-off-by: Dan Streetman <dan.streetman at canonical.com>
> ---
>  include/linux/mm.h | 12 ++++++++++++
>  mm/page_alloc.c    | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 64 insertions(+)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index e407dba..e446f8c 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1256,6 +1256,18 @@ static inline void pgtable_page_dtor(struct page *page)
>  extern void free_area_init(unsigned long * zones_size);
>  extern void free_area_init_node(int nid, unsigned long * zones_size,
>  		unsigned long zone_start_pfn, unsigned long *zholes_size);
> +
> +static inline unsigned long get_num_physpages(void)
> +{
> +	int nid;
> +	unsigned long phys_pages = 0;
> +
> +	for_each_online_node(nid)
> +		phys_pages += node_present_pages(nid);
> +
> +	return phys_pages;
> +}
> +
>  #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
>  /*
>   * With CONFIG_ARCH_POPULATES_NODE_MAP set, an architecture may initialise its
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 62a7fa23..c23df63 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -58,6 +58,7 @@
>  #include <linux/memcontrol.h>
>  #include <linux/prefetch.h>
>  
> +#include <asm/sections.h>
>  #include <asm/tlbflush.h>
>  #include <asm/div64.h>
>  #include "internal.h"
> @@ -5053,6 +5054,57 @@ early_param("movablecore", cmdline_parse_movablecore);
>  
>  #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
>  
> +
> +void __init mem_init_print_info(const char *str)
> +{
> +	unsigned long physpages, codesize, datasize, rosize, bss_size;
> +	unsigned long init_code_size, init_data_size;
> +
> +	physpages = get_num_physpages();
> +	codesize = _etext - _stext;
> +	datasize = _edata - _sdata;
> +	rosize = __end_rodata - __start_rodata;
> +	bss_size = __bss_stop - __bss_start;
> +	init_data_size = __init_end - __init_begin;
> +	init_code_size = _einittext - _sinittext;
> +
> +	/*
> +	 * Detect special cases and adjust section sizes accordingly:
> +	 * 1) .init.* may be embedded into .data sections
> +	 * 2) .init.text.* may be out of [__init_begin, __init_end],
> +	 *    please refer to arch/tile/kernel/vmlinux.lds.S.
> +	 * 3) .rodata.* may be embedded into .text or .data sections.
> +	 */
> +#define adj_init_size(start, end, size, pos, adj) \
> +	if (start <= pos && pos < end && size > adj) \
> +		size -= adj;
> +
> +	adj_init_size(__init_begin, __init_end, init_data_size,
> +		     _sinittext, init_code_size);
> +	adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size);
> +	adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size);
> +	adj_init_size(_stext, _etext, codesize, __start_rodata, rosize);
> +	adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize);
> +
> +#undef	adj_init_size
> +
> +	printk("Memory: %luK/%luK available "
> +	       "(%luK kernel code, %luK rwdata, %luK rodata, "
> +	       "%luK init, %luK bss, %luK reserved"
> +#ifdef	CONFIG_HIGHMEM
> +	       ", %luK highmem"
> +#endif
> +	       "%s%s)\n",
> +	       nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
> +	       codesize >> 10, datasize >> 10, rosize >> 10,
> +	       (init_data_size + init_code_size) >> 10, bss_size >> 10,
> +	       (physpages - totalram_pages) << (PAGE_SHIFT-10),
> +#ifdef	CONFIG_HIGHMEM
> +	       totalhigh_pages << (PAGE_SHIFT-10),
> +#endif
> +	       str ? ", " : "", str ? str : "");
> +}
> +
>  /**
>   * set_dma_reserve - set the specified number of pages reserved in the first zone
>   * @new_dma_reserve: The number of pages to mark reserved
> 

This patch will work, but what happened to the external reference in
linux/mm.h ?

+extern void mem_init_print_info(const char *str);

rtg
-- 
Tim Gardner tim.gardner at canonical.com