bg_ratio 401 mm/page-writeback.c unsigned long bg_ratio = (dirty_background_ratio * PAGE_SIZE) / 100; bg_ratio 421 mm/page-writeback.c bg_ratio = min(DIV_ROUND_UP(bg_bytes, global_avail), bg_ratio 434 mm/page-writeback.c bg_thresh = (bg_ratio * available_memory) / PAGE_SIZE;