This chapter describes the MDB features for execution control of the live operating system kernel available when running kmdb. kmdb is a version of MDB specifically designed for kernel execution control and live kernel debugging. Using kmdb, the kernel can be controlled and observed in much the same way that a user process can be controlled and observed using mdb. The kernel execution control functionality includes instruction-level control of kernel threads executing on each CPU, enabling developers to single-step the kernel and inspect data structures in real time.
Both mdb and kmdb share the same user interface. All of the execution control functionality described in Execution Control in MDB is available in kmdb, and is identical to the set of commands used to control user processes. The commands used to inspect kernel state, described in MDB Language Syntax and Built-In Commands in MDB, are also available when using kmdb. Finally, the commands specific to the Oracle Solaris kernel implementation, described in Kernel Debugging Modules, are available unless otherwise noted. This chapter describes the remaining features that are specific to kmdb.