* David Ahern <dsah...@gmail.com> wrote: > From: Pawel Moll <pawel.m...@arm.com> > > To co-relate user space events with the perf events stream > a current (as in: "what time(stamp) is it now?") time value > must be made available.
So I'm wondering about your earlier approach posted here: https://lkml.org/lkml/2011/6/7/636 I'd modify that patch the following way: instead of tracking each separate reason, perhaps only track timekeeping_update(). Such a tracepoint, combined with PERF_SAMPLE_TIME, would very accurately track external changes to GTOD (xtime). That leaves us with tracking/correlating the regular flow of time, which could be achieved by another tracepoint in: kernel/time/timekeeping.c::do_timer() So only two new tracepoints are needed AFAICS - and the tracepoints would obviously be useful for other (debugging) purposes as well. Would that solve the wall-clock correlation problem adequately? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
