Messages in this thread | | | Date | Fri, 15 Jun 2012 12:02:45 +0900 | From | Masami Hiramatsu <> | Subject | Re: [RFC][PATCH 02/13 v2] ftrace: Consolidate arch dependent functions with list function |
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(2012/06/13 7:43), Steven Rostedt wrote: > From: Steven Rostedt <srostedt@redhat.com> > > As the function tracer starts to get more features, the support for > theses features will spread out throughout the different architectures > over time. These features boil down to what each arch does in the > mcount trampoline (the ftrace_caller). > > Currently there's two features that are not the same throughout the > archs. > > 1) Support to stop function tracing before the callback > 2) passing of the ftrace ops > > Both of these require placing an indirect function to support the > features if the mcount trampoline does not. > > On a side note, for all architectures, when more than one callback > is registered to the function tracer, an intermediate 'list' function > is called by the mcount trampoline to iterate through the callbacks > that are registered. > > Instead of making a separate function for each of these features, > and requiring several indirect calls, just use the single 'list' function > as the intermediate, to handle all cases. If an arch does not support > the 'stop function tracing' or the passing of ftrace ops, just force > it to use the list function that will handle the features required.
Ah, I see. so even if the arch doesn't support passing ftrace_ops in mcount trampoline, this ensures that the correct ftrace_ops should be passed to the handlers.
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Thank you,
-- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
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