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

[Dan Streetman]

On Tue, Sep 13, 2016 at 10:01 AM, Tim Gardner <tim.gardner at canonical.com> wrote:
> 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);

doh!  I appear to have removed it accidentally when editing the
cherry-pick for the context differences.  I'll resend with it
included.

thanks!

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