Messages in this thread | | | Date | Fri, 16 Jan 2009 17:02:02 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 0/2] ftrace: updates to tip |
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* Steven Rostedt <rostedt@goodmis.org> wrote:
> > On Fri, 16 Jan 2009, Ingo Molnar wrote: > > > > > > But I do notice that not all functions produce a valid stack trace. > > > Maybe it would be better to add that api :-? > > > > yes - i think that API would be more intuitive, and that way people could > > mix more interesting functions (with stack traces) with less important > > functions (no stack traces). > > Ah, that's the point. We can't mix and match on these. Either all > functions that are traced do the stack trace, or none do. This is where > the new api may be confusing. [...]
that would be confusing indeed.
> [...] We can register a function to be traced via the function pointer, > and we can pick which functions to trace, but we can not separate out > different functions for different traces.
Why not? We could have a hash of all traced functions with metadata attached. Since patching functions in/out would be a relatively rare operation, this would be a highly efficient read-mostly hash.
Ingo
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