On Mon, Mar 26, 2018 at 01:56:50PM -0700, David Rientjes wrote:
>On Mon, 26 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@xxxxxxxxx>
>> ---
>> 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().
--
Wei Yang
Help you, Help me
