Messages in this thread | | | Date | Thu, 21 Apr 2022 10:08:59 -0400 | From | Steven Rostedt <> | Subject | Re: [RFC PATCH -next v2 3/4] arm64/ftrace: support dynamically allocated trampolines |
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On Thu, 21 Apr 2022 10:06:39 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> Without this change, because the arch does not support dynamically > allocated trampolines, it means that all these ftrace_ops will be > registered to the same trampoline. That means, for every function that is > traced, it will loop through all 10 of theses ftrace_ops and check their > hashes to see if their callback should be called or not.
Oh, I forgot to mention. If you then enable function tracer that traces *every function*, then *every function* will be going through this loop of the 10 ftrace_ops!
With dynamically allocated trampolines, then most functions will just call the trampoline that handles the function tracer directly.
-- Steve
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