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SubjectRe: [PATCH 1/2] mm: reuse pageblock_start/end_pfn() macro
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On 2022/9/2 16:20, David Hildenbrand wrote:
> On 02.09.22 08:47, Kefeng Wang wrote:
>> Move pageblock_start_pfn/pageblock_end_pfn() into pageblock-flags.h,
>> then they could be used somewhere else, not only in compaction.
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>> include/linux/pageblock-flags.h | 2 ++
>> mm/compaction.c | 2 --
>> mm/memblock.c | 2 +-
>> mm/page_alloc.c | 13 ++++++-------
>> mm/page_isolation.c | 2 +-
>> mm/page_owner.c | 4 ++--
>> 6 files changed, 12 insertions(+), 13 deletions(-)
>>
>> diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h
>> index 83c7248053a1..ef2e17e312ae 100644
>> --- a/include/linux/pageblock-flags.h
>> +++ b/include/linux/pageblock-flags.h
>> @@ -53,6 +53,8 @@ extern unsigned int pageblock_order;
>> #endif /* CONFIG_HUGETLB_PAGE */
>>
>> #define pageblock_nr_pages (1UL << pageblock_order)
>> +#define pageblock_start_pfn(pfn) round_down(pfn, pageblock_nr_pages)
>> +#define pageblock_end_pfn(pfn) ALIGN((pfn + 1), pageblock_nr_pages)
>>
> I'd naturally have paired ALIGN with ALIGN_DOWN -- or round_up with round_down.
> (You're replacing one instance where ALIGN_DOWN was used at least.)

I think they are same for pageblock usage,but the original macro
introduced from Vlastimil

(06b6640a3902 mm, compaction: wrap calculating first and last pfn of
pageblock), let's

wait for Vlastimil to see if there are some background.

>
> But maybe there is an obvious reason that I am missing :)
>
>> /* Forward declaration */
>> struct page;
>> diff --git a/mm/compaction.c b/mm/compaction.c
>> index f72907c7cfef..65bef5f78897 100644
>> --- a/mm/compaction.c
>> +++ b/mm/compaction.c
>> @@ -52,8 +52,6 @@ static inline void count_compact_events(enum vm_event_item item, long delta)
>>
>> #define block_start_pfn(pfn, order) round_down(pfn, 1UL << (order))
>> #define block_end_pfn(pfn, order) ALIGN((pfn) + 1, 1UL << (order))
>> -#define pageblock_start_pfn(pfn) block_start_pfn(pfn, pageblock_order)
>> -#define pageblock_end_pfn(pfn) block_end_pfn(pfn, pageblock_order)
>>
>> /*
>> * Page order with-respect-to which proactive compaction
>> diff --git a/mm/memblock.c b/mm/memblock.c
>> index b5d3026979fc..46fe7575f03c 100644
>> --- a/mm/memblock.c
>> +++ b/mm/memblock.c
>> @@ -2000,7 +2000,7 @@ static void __init free_unused_memmap(void)
>> * presume that there are no holes in the memory map inside
>> * a pageblock
>> */
>> - start = round_down(start, pageblock_nr_pages);
>> + start = pageblock_start_pfn(start);
>>
>> /*
>> * If we had a previous bank, and there is a space
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 36b20215a3be..93339cc61f92 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -544,7 +544,7 @@ static inline int pfn_to_bitidx(const struct page *page, unsigned long pfn)
>> #ifdef CONFIG_SPARSEMEM
>> pfn &= (PAGES_PER_SECTION-1);
>> #else
>> - pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages);
>> + pfn = pfn - pageblock_start_pfn(page_zone(page)->zone_start_pfn);
>> #endif /* CONFIG_SPARSEMEM */
>> return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
>> }
>> @@ -1857,7 +1857,7 @@ void set_zone_contiguous(struct zone *zone)
>> unsigned long block_start_pfn = zone->zone_start_pfn;
>> unsigned long block_end_pfn;
>>
>> - block_end_pfn = ALIGN(block_start_pfn + 1, pageblock_nr_pages);
>> + block_end_pfn = pageblock_end_pfn(block_start_pfn);
>> for (; block_start_pfn < zone_end_pfn(zone);
>> block_start_pfn = block_end_pfn,
>> block_end_pfn += pageblock_nr_pages) {
>> @@ -2653,8 +2653,8 @@ int move_freepages_block(struct zone *zone, struct page *page,
>> *num_movable = 0;
>>
>> pfn = page_to_pfn(page);
>> - start_pfn = pfn & ~(pageblock_nr_pages - 1);
>> - end_pfn = start_pfn + pageblock_nr_pages - 1;
>> + start_pfn = pageblock_start_pfn(pfn);
>> + end_pfn = pageblock_end_pfn(pfn) - 1;
>>
>> /* Do not cross zone boundaries */
>> if (!zone_spans_pfn(zone, start_pfn))
>> @@ -6939,9 +6939,8 @@ static void __init init_unavailable_range(unsigned long spfn,
>> u64 pgcnt = 0;
>>
>> for (pfn = spfn; pfn < epfn; pfn++) {
>> - if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) {
>> - pfn = ALIGN_DOWN(pfn, pageblock_nr_pages)
>> - + pageblock_nr_pages - 1;
>> + if (!pfn_valid(pageblock_start_pfn(pfn))) {
>> + pfn = pageblock_end_pfn(pfn) - 1;
>> continue;
>> }
>> __init_single_page(pfn_to_page(pfn), pfn, zone, node);
>> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
>> index 9d73dc38e3d7..f2df4ad53cd6 100644
>> --- a/mm/page_isolation.c
>> +++ b/mm/page_isolation.c
>> @@ -172,7 +172,7 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_
>> * to avoid redundant checks.
>> */
>> check_unmovable_start = max(page_to_pfn(page), start_pfn);
>> - check_unmovable_end = min(ALIGN(page_to_pfn(page) + 1, pageblock_nr_pages),
>> + check_unmovable_end = min(pageblock_end_pfn(page_to_pfn(page)),
>> end_pfn);
>>
>
> There are some more cases that might need care as well:
>
>
> mm/memblock.c: prev_end = ALIGN(end, pageblock_nr_pages);
> mm/memblock.c: prev_end = ALIGN(end, pageblock_nr_pages);
> mm/page_isolation.c: VM_BUG_ON(ALIGN_DOWN(start_pfn, pageblock_nr_pages) !=
> mm/page_isolation.c: ALIGN_DOWN(end_pfn - 1, pageblock_nr_pages));
> mm/page_isolation.c: unsigned long isolate_start = ALIGN_DOWN(start_pfn, pageblock_nr_pages);
> mm/page_isolation.c: unsigned long isolate_end = ALIGN(end_pfn, pageblock_nr_pages);
> mm/page_isolation.c: unsigned long isolate_start = ALIGN_DOWN(start_pfn, pageblock_nr_pages);
> mm/page_isolation.c: unsigned long isolate_end = ALIGN(end_pfn, pageblock_nr_pages);

ok, will update.

>
>
>

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