PIPE_DEPTH         22 arch/ia64/lib/copy_page.S #define PIPE_DEPTH	3
PIPE_DEPTH         40 arch/ia64/lib/copy_user.S #define PIPE_DEPTH	21	// pipe depth
PIPE_DEPTH        121 arch/ia64/lib/do_csum.S #define PIPE_DEPTH			(LOAD_LATENCY+2)