Hi, What is the rationale behind having, for some feature XXX, both configuration macros CONFIG_XXX and CONFIG_HAVE_XXX ? For example, I'd love to use ftrace's new life-saving feature "funcgraph-retval" (which instantly shows the root cause of an error returned from a fully graphed function). Unfortunately, on all recent Debians the config says: CONFIG_HAVE_FUNCTION_GRAPH_RETVAL=y # CONFIG_FUNCTION_GRAPH_RETVAL is not set As a result, the feature is not available. Okay, I'll just enable and recompile. However, I'm wondering why in the first place such a situation is possible: what is the intention there ? Either we want the feature, or we don't (e.g. because it may incur some CPU or memory overhead), but why sit halfway in between ? Thanks in advance, -Alex