Re: [PATCH] mm/mm_init: use helper macro BITS_PER_LONG

From: Miaohe Lin
Date: Thu Aug 03 2023 - 21:53:25 EST


On 2023/8/3 21:33, Mike Rapoport wrote:
> On Thu, Aug 03, 2023 at 07:40:51PM +0800, Miaohe Lin wrote:
>> It's more readable to use helper macro BITS_PER_LONG. No functional
>> change intended.
>>
>> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
>> ---
>> mm/mm_init.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/mm/mm_init.c b/mm/mm_init.c
>> index 66aca3f6accd..2f37dbb5ff9a 100644
>> --- a/mm/mm_init.c
>> +++ b/mm/mm_init.c
>> @@ -79,7 +79,7 @@ void __init mminit_verify_pageflags_layout(void)
>> int shift, width;
>> unsigned long or_mask, add_mask;
>>
>> - shift = 8 * sizeof(unsigned long);
>> + shift = BITS_PER_LONG;
>> width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH
>> - LAST_CPUPID_SHIFT - KASAN_TAG_WIDTH - LRU_GEN_WIDTH - LRU_REFS_WIDTH;
>> mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
>> @@ -1431,7 +1431,7 @@ static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned l
>> usemapsize = roundup(zonesize, pageblock_nr_pages);
>> usemapsize = usemapsize >> pageblock_order;
>> usemapsize *= NR_PAGEBLOCK_BITS;
>> - usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
>> + usemapsize = roundup(usemapsize, BITS_PER_LONG);
>>
>> return usemapsize / 8;
>
> BITS_PER_BYTE instead of 8 here?

Sure, this is even better. Will do.

Thanks.