Re: [PATCH -v4 4/9] tracing: add static function tracer supportfor MIPS

From: Adam Nemet
Date: Thu Oct 22 2009 - 17:31:33 EST


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.

Adam
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