__collapse_huge_page_isolate() may fail due to extra pin in the LRU add pagevec. It's pretty common for swapin case: we swap in pages just to fail due to the extra pin. Drain LRU add pagevec on successful swapin. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> Reviewed-and-Tested-by: Zi Yan <ziy@xxxxxxxxxx> Acked-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> --- mm/khugepaged.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 0b75b9821f44..adc686f13447 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -931,6 +931,11 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, } vmf.pte--; pte_unmap(vmf.pte); + + /* Drain LRU add pagevec to remove extra pin on the swapped in pages */ + if (swapped_in) + lru_add_drain(); + trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 1); return true; } -- 2.26.1
