On Thu, 2009-10-22 at 14:29 -0700, Adam Nemet wrote:
quoted text
> 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


--
unsubscribe notice
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/