WMARK_LOW         328 include/linux/mmzone.h #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
WMARK_LOW         504 mm/internal.h  #define ALLOC_WMARK_LOW		WMARK_LOW
WMARK_LOW        7795 mm/page_alloc.c 		zone->_watermark[WMARK_LOW]  = min_wmark_pages(zone) + tmp;