Messages in this thread | | | Date | Tue, 3 Jan 2023 09:58:36 +0800 | Subject | Re: [PATCH v2] mm: huge_memory: convert split_huge_pages_all() to use a folio | From | Kefeng Wang <> |
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On 2022/12/31 5:45, Andrew Morton wrote: > On Fri, 30 Dec 2022 17:30:20 +0800 Kefeng Wang <wangkefeng.wang@huawei.com> wrote: > >> Straightforwardly convert split_huge_pages_all() to use a folio. >> >> ... >> >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -2932,6 +2932,7 @@ static void split_huge_pages_all(void) >> { >> struct zone *zone; >> struct page *page; >> + struct folio *folio; >> unsigned long pfn, max_zone_pfn; >> unsigned long total = 0, split = 0; >> >> @@ -2944,24 +2945,32 @@ static void split_huge_pages_all(void) >> int nr_pages; >> >> page = pfn_to_online_page(pfn); >> - if (!page || !get_page_unless_zero(page)) >> + if (!page || PageTail(page)) >> + continue; >> + folio = page_folio(page); >> + if (!folio_try_get(folio)) >> continue; >> >> - if (zone != page_zone(page)) >> + if (unlikely(page_folio(page) != folio)) >> + goto next; >> + >> + if (zone != folio_zone(folio)) >> goto next; > > I'm still not understanding the above hunk. Why is the > "page_folio(page) != folio" check added? Should it be commented?
There is a comment in try_get_folio(), is it enough?
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