Re: [PATCH 1/2] mm/sparse: pass the __highest_present_section_nr + 1 to alloc_func()

[Wei Yang <richard.weiyang@gmail.com>]

On Mon, Mar 26, 2018 at 03:47:03PM -0700, David Rientjes wrote:
>On Tue, 27 Mar 2018, Wei Yang wrote:
>
>> >> In 'commit c4e1be9ec113 ("mm, sparsemem: break out of loops early")',
>> >> __highest_present_section_nr is introduced to reduce the loop counts for
>> >> present section. This is also helpful for usemap and memmap allocation.
>> >> 
>> >> This patch uses __highest_present_section_nr + 1 to optimize the loop.
>> >> 
>> >> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> >> ---
>> >>  mm/sparse.c | 2 +-
>> >>  1 file changed, 1 insertion(+), 1 deletion(-)
>> >> 
>> >> diff --git a/mm/sparse.c b/mm/sparse.c
>> >> index 7af5e7a92528..505050346249 100644
>> >> --- a/mm/sparse.c
>> >> +++ b/mm/sparse.c
>> >> @@ -561,7 +561,7 @@ static void __init alloc_usemap_and_memmap(void (*alloc_func)
>> >>  		map_count = 1;
>> >>  	}
>> >>  	/* ok, last chunk */
>> >> -	alloc_func(data, pnum_begin, NR_MEM_SECTIONS,
>> >> +	alloc_func(data, pnum_begin, __highest_present_section_nr+1,
>> >>  						map_count, nodeid_begin);
>> >>  }
>> >>  
>> >
>> >What happens if s/NR_MEM_SECTIONS/pnum/?
>> 
>> I have tried this :-)
>> 
>> The last pnum is -1 from next_present_section_nr().
>> 
>
>Lol.  I think it would make more sense for the second patch to come before 
>the first, but feel free to add
>

Thanks for your comment.

Do I need to reorder the patch and send v2?

>Acked-by: David Rientjes <rientjes@google.com>

-- 
Wei Yang
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