LINUX KERNEL ACTIVATIONS TO SUPPORTMULTITHREADING

摘要

This paper describes a modifcation to the Linuxrnoperating system kernel that implements a mechanismrncalled scheduler activations" for supporting user-levelrnmultithreading. The key idea is to allow a user-levelrnthread package to implement its own scheduling andrnto provide a mechanism whereby the kernel will notifyrnthis package whenever it (the kernel) makes a schedulingrndecision that au000bects one of the kernel-level threadsrnutilized by the package. Based on this notifcation, thernuser-level scheduler decides which user-level threads tornrun. Tests show that a scheduler adapted to utilizernthis new mechanism gives performance comparable tornthe performance of a user-level scheduler when no I/Ornoperations are involved.