----- Original Message ----- > From: "Peter Zijlstra" <[email protected]> > To: "Thomas Gleixner" <[email protected]> > Cc: "LKML" <[email protected]>, "John Stultz" > <[email protected]>, "Steven Rostedt" > <[email protected]>, "Mathieu Desnoyers" <[email protected]> > Sent: Monday, July 14, 2014 5:47:50 AM > Subject: Re: [patch 54/55] timekeeping: Provide fast and NMI safe access to > CLOCK_MONOTONIC[_RAW] > > On Fri, Jul 11, 2014 at 01:45:19PM -0000, Thomas Gleixner wrote: > > +static struct tk_fast tk_fast_raw ____cacheline_aligned; > > +static struct tk_fast tk_fast_mono ____cacheline_aligned; > > Question to the 'trace maniacs'; why do you lot need access to mono_raw? > > I would much prefer to limit choice here.
For LTTng, which I guess qualifies as bring part of the aforementioned trace maniacs group, we only need the "tk_fast_mono" clock. We don't need mono_raw. We can then correlate with user-space traces by using tk_fast_mono in kernel-space and using CLOCK_MONOTONIC in userspace. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
