Messages in this thread | | | Date | Mon, 14 Jul 2014 16:15:35 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [patch 54/55] timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC[_RAW] |
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On Mon, 14 Jul 2014, Mathieu Desnoyers wrote:
> ----- Original Message ----- > > From: "Peter Zijlstra" <peterz@infradead.org> > > To: "Thomas Gleixner" <tglx@linutronix.de> > > Cc: "LKML" <linux-kernel@vger.kernel.org>, "John Stultz" <john.stultz@linaro.org>, "Steven Rostedt" > > <rostedt@goodmis.org>, "Mathieu Desnoyers" <mathieu.desnoyers@efficios.com> > > 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.
I'm happy to ditch the raw one ...
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