[$] A framework for code tagging

Kernel code can, at times, be quite inward looking; it often refers toitself. To enable this introspection, the kernel has evolved severalmechanisms for identifying specific locations in the code and carrying outactions related to those locations. The code-taggingframework patch set, posted by Suren Baghdasaryan and Kent Overstreet,is an attempt to replace various ad hoc implementations with asingle framework, and to add some new applications as well.