From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm: remove the total_mapcount argument from page_trans_huge_mapcount() All callers pass NULL, so we can stop calculating the value we would store in it. Link: https://lkml.kernel.org/r/20211220205943.456187-3-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> Acked-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm.h | 10 +++------- include/linux/swap.h | 2 +- mm/huge_memory.c | 30 ++++++++++-------------------- mm/swapfile.c | 2 +- 4 files changed, 15 insertions(+), 29 deletions(-) --- a/include/linux/mm.h~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount +++ a/include/linux/mm.h @@ -799,19 +799,15 @@ static inline int page_mapcount(struct p #ifdef CONFIG_TRANSPARENT_HUGEPAGE int total_mapcount(struct page *page); -int page_trans_huge_mapcount(struct page *page, int *total_mapcount); +int page_trans_huge_mapcount(struct page *page); #else static inline int total_mapcount(struct page *page) { return page_mapcount(page); } -static inline int page_trans_huge_mapcount(struct page *page, - int *total_mapcount) +static inline int page_trans_huge_mapcount(struct page *page) { - int mapcount = page_mapcount(page); - if (total_mapcount) - *total_mapcount = mapcount; - return mapcount; + return page_mapcount(page); } #endif --- a/include/linux/swap.h~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount +++ a/include/linux/swap.h @@ -681,7 +681,7 @@ static inline int swp_swapcount(swp_entr } #define reuse_swap_page(page) \ - (page_trans_huge_mapcount(page, NULL) == 1) + (page_trans_huge_mapcount(page) == 1) static inline int try_to_free_swap(struct page *page) { --- a/mm/huge_memory.c~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount +++ a/mm/huge_memory.c @@ -2542,38 +2542,28 @@ int total_mapcount(struct page *page) * need full accuracy to avoid breaking page pinning, because * page_trans_huge_mapcount() is slower than page_mapcount(). */ -int page_trans_huge_mapcount(struct page *page, int *total_mapcount) +int page_trans_huge_mapcount(struct page *page) { - int i, ret, _total_mapcount, mapcount; + int i, ret; /* hugetlbfs shouldn't call it */ VM_BUG_ON_PAGE(PageHuge(page), page); - if (likely(!PageTransCompound(page))) { - mapcount = atomic_read(&page->_mapcount) + 1; - if (total_mapcount) - *total_mapcount = mapcount; - return mapcount; - } + if (likely(!PageTransCompound(page))) + return atomic_read(&page->_mapcount) + 1; page = compound_head(page); - _total_mapcount = ret = 0; + ret = 0; for (i = 0; i < thp_nr_pages(page); i++) { - mapcount = atomic_read(&page[i]._mapcount) + 1; + int mapcount = atomic_read(&page[i]._mapcount) + 1; ret = max(ret, mapcount); - _total_mapcount += mapcount; } - if (PageDoubleMap(page)) { + + if (PageDoubleMap(page)) ret -= 1; - _total_mapcount -= thp_nr_pages(page); - } - mapcount = compound_mapcount(page); - ret += mapcount; - _total_mapcount += mapcount; - if (total_mapcount) - *total_mapcount = _total_mapcount; - return ret; + + return ret + compound_mapcount(page); } /* Racy check whether the huge page can be split */ --- a/mm/swapfile.c~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount +++ a/mm/swapfile.c @@ -1619,7 +1619,7 @@ static int page_trans_huge_map_swapcount swapcount = page_swapcount(page); if (total_swapcount) *total_swapcount = swapcount; - return swapcount + page_trans_huge_mapcount(page, NULL); + return swapcount + page_trans_huge_mapcount(page); } page = compound_head(page); _
