FILTER MASKS

底下的『mask』將會被用『-a』option來傳遞，多重的濾鏡可以用多重的『-a』來結合：

barrier: barrier attribute
complete: completed by driver
fs: requests
issue: issued to driver
pc: packet command events
queue: queue operations
read: read traces
requeue: requeue operations
sync: synchronous attribute
write: write traces
notify: trace messages
drv_data: additional driver specific trace