Re: [tip:timers/tracing] hrtimer: Add tracepoint for hrtimers

From: Steven Rostedt
Date: Tue Oct 13 2009 - 10:05:27 EST


On Tue, 2009-10-13 at 15:26 +0200, Ingo Molnar wrote:
> * Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> > On Tue, 2009-10-13 at 09:08 +0200, Ingo Molnar wrote:
> > > * Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> > >
> >
> > > > (unsigned long long)(((ktime_t) { .tv64 = REC->expires }).tv64)
> > > >
> > > > Is not easy. It's basically implementing a C interpreter :-(
> > >
> > > Btw., what i suggested quite some time ago was that we should bind
> > > tracepoints by emitting C source code stubs, which tools can then build
> > > and link in, using gcc.
> >
> > Yeah, and I thought about that too. But that kills any chance of
> > running the trace on one box (non x86) and reading it on another
> > (x86). And that is one of my goals for this.
>
> Why does it kill that chance?

Ah, I was thinking binary libraries from the trace points. But I missed
you said C source code.

But still, we need to build a way to convert big endian to little, as
well as perhaps converting 32bit to 64 bit longs. As well as vice versa.

We also need a way to export all structures (here ktime_t) as well as
enums. Of course we need to export enums now anyway, since the tools
don't know how to convert them now.

-- Steve


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