Messages in this thread | | | Date | Fri, 17 Jun 2011 16:19:15 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 1/6] trace: add tracepoints to timekeeping code - xtime changes |
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On Fri, Jun 17, 2011 at 08:13:19AM -0600, David Ahern wrote: > > > On 06/17/2011 07:23 AM, Frederic Weisbecker wrote: > > On Tue, Jun 07, 2011 at 05:55:03PM -0600, David Ahern wrote: > >> Trace points in timekeeping.c where xtime is modified by a user > >> or ntp. > >> > >> Signed-off-by: David Ahern <dsahern@gmail.com> > >> --- > >> include/trace/events/timekeeping.h | 43 ++++++++++++++++++++++++++++++++++++ > >> kernel/time/timekeeping.c | 8 ++++++ > >> 2 files changed, 51 insertions(+), 0 deletions(-) > >> create mode 100644 include/trace/events/timekeeping.h > >> > >> diff --git a/include/trace/events/timekeeping.h b/include/trace/events/timekeeping.h > >> new file mode 100644 > >> index 0000000..3d5d083 > >> --- /dev/null > >> +++ b/include/trace/events/timekeeping.h > >> @@ -0,0 +1,43 @@ > >> +#undef TRACE_SYSTEM > >> +#define TRACE_SYSTEM timekeeping > >> + > >> +#if !defined(_TRACE_TIMEKEEP_H) || defined(TRACE_HEADER_MULTI_READ) > >> +#define _TRACE_TIMEKEEP_H > >> + > >> +#include <linux/tracepoint.h> > >> +#include <linux/time.h> > >> + > >> +DECLARE_EVENT_CLASS(tod_template, > >> + > >> + TP_PROTO(const struct timespec *tv), > >> + > >> + TP_ARGS(tv), > >> + > >> + TP_STRUCT__entry( > >> + __field( __kernel_time_t, tv_sec) > >> + __field( long, tv_nsec) > >> + ), > >> + > >> + TP_fast_assign( > >> + __entry->tv_sec = tv->tv_sec; > >> + __entry->tv_nsec = tv->tv_nsec; > >> + ), > >> + > >> + TP_printk("tv_sec=%ld tv_nsec=%ld", __entry->tv_sec, __entry->tv_nsec) > >> +); > >> + > >> +DEFINE_EVENT(tod_template, settimeofday, > >> + TP_PROTO(const struct timespec *tv), > >> + TP_ARGS(tv)); > >> + > >> +DEFINE_EVENT(tod_template, timekeeping_inject_offset, > >> + TP_PROTO(const struct timespec *tv), > >> + TP_ARGS(tv)); > >> + > >> +DEFINE_EVENT(tod_template, timekeeping_inject_sleeptime, > >> + TP_PROTO(const struct timespec *tv), > >> + TP_ARGS(tv)); > > > > Does the fact it's any of the three way of updating xtime make any > > difference from the user point of view? > > This use case only cares that xtime is updated. > > > > > If not can we rather factorize that in a single settimeofday tracepoint? > > Or update_time_of_day if we don't want to confuse the user with the > > syscall. > > Peter and Thomas expressed interest in timekeeping tracepoints. How the > update happens might be wanted. If desired I can consolidate xtime = *tv > into a single update function and put the trace point there.
Peter, Thomas, any opinion about that?
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