In this chapter, we explore tools that can be used to monitor performance of kernel subsystems, drivers and other loadable kernel modules.
There are several tools available in the Solaris environment to measure and optimize the performance of kernel code and device drivers. The following tasks are the most common:
Identify the reason for high system time (
mpstat %sys). We can use a kernel profile (DTrace or
lockstat -I) or trace (DTrace) to produce a ranked list of system calls, functions, modules, drivers, or subsystems that are contributing to system time.
Identify the reason for nonscalability on behalf of a system call. Typically, our approach is to observe the wall clock time and CPU cycles ...