Messages in this thread | | | Subject | Re: [PATCH -v4 4/9] tracing: add static function tracer support for MIPS | From | Steven Rostedt <> | Date | Thu, 22 Oct 2009 17:55:17 -0400 |
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On Thu, 2009-10-22 at 14:29 -0700, Adam Nemet wrote: > Steven Rostedt writes: > > On Thu, 2009-10-22 at 13:30 -0700, Adam Nemet wrote: > > > Also note that for functions invoked via tail call you won't get an exit > > > event. E.g. if bar is tail-called from foo: > > > > > > foo entered > > > bar entered > > > foo/bar exited > > > > > > However, this is not MIPS-specific and you can always disable tail calls > > > with -fno-optimize-sibling-calls. > > > > The question is, would bar have a _mcount call? So far, we have not had > > any issues with this on either x86 nor PPC. > > Yes, bar will have an _mcount call. The difference is that bar will return to > foo's caller directly rather than to foo first.
I guess the best bet is to have CONFIG_FUNCTION_GRAPH enable -fno-optimize-sibling-calls and be done with it.
-- Steve
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