On Mon, Oct 26, 2009 at 05:42:36PM +0800, Wu Zhangjin wrote: > On Mon, 2009-10-26 at 01:27 +0100, Frederic Weisbecker wrote: > > 2009/10/25 Wu Zhangjin <wuzhangjin@xxxxxxxxx>: > > > -static inline u64 mips_timecounter_read(void) > > > +static inline u64 notrace mips_timecounter_read(void) > > > > > > You don't need to set notrace functions, unless their addresses > > are referenced somewhere, which unfortunately might happen > > for some functions but this is rare. > > > > Okay, Will remove it. Oops, a word has escaped from my above sentence. I wanted to say: "You don't need to set notrace to inline functions" :) > > Hmm yeah this is not very nice to do that in core functions because > > of a specific arch problem. > > At least you have __notrace_funcgraph, this is a notrace > > that only applies if CONFIG_FUNCTION_GRAPH_TRACER > > so that it's still traceable by the function tracer in this case. > > > > But I would rather see a __mips_notrace on these two core functions. > > What about this: __arch_notrace? If the arch need this, define it, > otherwise, ignore it! if only graph tracer need it, define it in "#ifdef > CONFIG_FUNCTION_GRAPH_TRACER ... #endif". The problem is that archs may want to disable tracing on different places. For example mips wants to disable tracing in timecounter_read_delta, but another arch may want to disable tracing somewhere else. We'll then have several unrelated __arch_notrace. One that is relevant for mips, another that is relevant for arch_foo, but all of them will apply for all arch that have defined a __arch_notrace. It's true that __mips_notrace is not very elegant as it looks like a specific arch annotation intruder. But at least that gives us a per arch filter granularity. If only static ftrace could disappear, we could keep only dynamic ftrace and we would then be able to filter dynamically. But I'm not sure it's a good idea for archs integration.
