From help-file :
The simplest PRIO pseudo scheduler CONFIG_NET_SCH_PRIO Say Y here if you want to use an n-band priority queue packet "scheduler" for some of your network devices or as a leaf discipline for the CBQ scheduling algorithm. If unsure, say Y. This code is also available as a module called sch_prio.o ( = code which can be inserted in and removed from the running kernel whenever you want). If you want to compile it as a module, say M here and read Documentation/modules.txt.
From source-files :
ONFIG_NET_SCH_PRIO: Say Y here if you want to use an n-band priority queue packet "scheduler" for some of your network devices or as a leaf discipline for the CBQ scheduling algorithm. If unsure, say Y. This code is also available as a module called sch_prio.o ( = code which can be inserted in and removed from the running kernel whenever you want). If you want to compile it as a module, say M here and read Documentation/modules.txt.