Messages in this thread | | | Subject | Re: dynamic function tracing | From | Steven Rostedt <> | Date | Sun, 30 Nov 2008 20:58:50 -0500 |
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On Fri, 2008-11-28 at 10:19 -0800, Arjan van de Ven wrote: > Hi, > > I like the new function trace format with the {}'s a lot.. but I would > like to use it in a way I don't think would work with dynamic tracing. > > What I would like to do (read: usecase) is mark a function as > interesting (because it has some performance issue or whatever), > and then I want to get all functions it calls (recursive) traced > automatically for the duration of that function. > > This might be implementable by, on hitting the function to trace, > patching all trace points with a function that checks if it's this > thread (eg this "current"), and if so, traces the call. > I realize it's not going to be super cheap, so it needs to be one-shot, > but it'll form a really strong usecase in practice...
It would not be wise to enable the function pointer at that moment. But what we could do is have a function trace enabled that will flag when a function is hit. Then it could start tracing all functions until it returns. This would be possible.
What we need is a better way to attach the function tracer with the function graph.
-- Steve
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