On 4/13/20 5:52 AM, Kirill A. Shutemov wrote:
__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> --- mm/khugepaged.c | 5 +++++ 1 file changed, 5 insertions(+)
Acked-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index ee66c140c2d6..e3e41c2768d8 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -934,6 +934,11 @@ 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; }
