From: Oscar Salvador <osalvador@xxxxxxx> Subject: mm,hugetlb: split prep_new_huge_page functionality Currently, prep_new_huge_page() performs two functions. It sets the right state for a new hugetlb, and increases the hstate's counters to account for the new page. Let us split its functionality into two separate functions, decoupling the handling of the counters from initializing a hugepage. The outcome is having __prep_new_huge_page(), which only initializes the page , and __prep_account_new_huge_page(), which adds the new page to the hstate's counters. This allows us to be able to set a hugetlb without having to worry about the counter/locking. It will prove useful in the next patch. prep_new_huge_page() still calls both functions. Link: https://lkml.kernel.org/r/20210419075413.1064-5-osalvador@xxxxxxx Signed-off-by: Oscar Salvador <osalvador@xxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) --- a/mm/hugetlb.c~mmhugetlb-split-prep_new_huge_page-functionality +++ a/mm/hugetlb.c @@ -1484,16 +1484,30 @@ void free_huge_page(struct page *page) } } -static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) +/* + * Must be called with the hugetlb lock held + */ +static void __prep_account_new_huge_page(struct hstate *h, int nid) +{ + lockdep_assert_held(&hugetlb_lock); + h->nr_huge_pages++; + h->nr_huge_pages_node[nid]++; +} + +static void __prep_new_huge_page(struct page *page) { INIT_LIST_HEAD(&page->lru); set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); hugetlb_set_page_subpool(page, NULL); set_hugetlb_cgroup(page, NULL); set_hugetlb_cgroup_rsvd(page, NULL); +} + +static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) +{ + __prep_new_huge_page(page); spin_lock_irq(&hugetlb_lock); - h->nr_huge_pages++; - h->nr_huge_pages_node[nid]++; + __prep_account_new_huge_page(h, nid); spin_unlock_irq(&hugetlb_lock); } _
