On Thu, Sep 14, 2023 at 12:49:37AM +0800, Vern Hao wrote: > @@ -296,6 +295,7 @@ static void swap_writepage_fs(struct page *page, struct writeback_control *wbc) > struct file *swap_file = sis->swap_file; > loff_t pos = page_file_offset(page); > > + count_swpout_vm_event(page_folio(sio->bvec[p].bv_page)); Argh, this should be count_swpout_vm_event(page_folio(page));