Messages in this thread | | | Date | Mon, 17 Aug 2009 18:49:11 +0200 | From | Frederic Weisbecker <> | Subject | Re: [RFC PATCH] Add timer-source of walltime for ftrace |
| |
On Mon, Aug 17, 2009 at 05:22:04PM +0800, Zhaolei wrote: > We can add a timer-source for ftrace to support wall-time display. > It is based on Steven Rostedt <rostedt@goodmis.org>'s suggestion in: > http://lkml.org/lkml/2009/7/24/103 > > It needs to be applied on my patch of: > [PATCH v4 1/2] Add function to convert between calendar time and broken-down time for universal use > and > [PATCH v2 2/2] ftrace: Unify effect of writing to trace_options and option/* > > We can get following output: > # cd /mnt/debugfs/tracing/ > # ls options/*clock > options/global-clock options/local-clock options/walltime-clock > # echo sched_switch > current_tracer > # cat trace > # tracer: sched_switch > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > bash-3560 [000] 694.242386: 3560:120:S + [000] 3560:120:S bash > bash-3560 [000] 694.242476: 3560:120:S + [000] 3560:120:S bash > bash-3560 [000] 694.242865: 3560:120:R + [000] 5:115:S events/0 > bash-3560 [000] 694.242912: 3560:120:R ==> [000] 5:115:R events/0 > events/0-5 [000] 694.243015: 5:115:R + [000] 3558:120:S sshd > events/0-5 [000] 694.243040: 5:115:S ==> [000] 3560:120:R bash > bash-3560 [000] 694.243312: 3560:120:S + [000] 3560:120:S bash > bash-3560 [000] 694.243374: 3560:120:S ==> [000] 3558:120:R sshd > ... > # echo 1 > options/walltime-clock > # echo > trace > # cat trace > # tracer: sched_switch > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > bash-3560 [000] 2009-08-17 23:58:22 3560:120:S + [000] 3560:120:S bash > bash-3560 [000] 2009-08-17 23:58:22 3560:120:R + [000] 5:115:S events/0 > bash-3560 [000] 2009-08-17 23:58:22 3560:120:R ==> [000] 5:115:R events/0 > events/0-5 [000] 2009-08-17 23:58:22 5:115:R + [000] 3558:120:S sshd > events/0-5 [000] 2009-08-17 23:58:22 5:115:S ==> [000] 3558:120:R sshd > sshd-3558 [000] 2009-08-17 23:58:22 3558:120:S ==> [000] 3560:120:R bash > bash-3560 [000] 2009-08-17 23:58:22 3560:120:S + [000] 3560:120:S bash > bash-3560 [000] 2009-08-17 23:58:22 3560:120:S + [000] 3560:120:S bash > ... > > Note: > It is only a prototype patch to for demostrate what is result looks like. > There still have many works to do(bug to fix) before apply. > For example, we need to add a hook(tracepoint) of xtime change event, > so we can update walltime's clock base then. > And maybe we need clear all events when changing clock-source, because old > clock value can't displayed correctly in new clock's format. > > Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> > --- > include/linux/trace_clock.h | 1 + > kernel/trace/trace.c | 55 ++++++++++++++++++++++++++++++------------ > kernel/trace/trace.h | 6 +++- > kernel/trace/trace_clock.c | 47 ++++++++++++++++++++++++++++++++++++ > kernel/trace/trace_output.c | 20 ++++++++++++--- > 5 files changed, 107 insertions(+), 22 deletions(-) > > diff --git a/include/linux/trace_clock.h b/include/linux/trace_clock.h > index 7a81303..322707e 100644 > --- a/include/linux/trace_clock.h > +++ b/include/linux/trace_clock.h > @@ -15,5 +15,6 @@ > extern u64 notrace trace_clock_local(void); > extern u64 notrace trace_clock(void); > extern u64 notrace trace_clock_global(void); > +extern u64 notrace trace_clock_walltime(void); > > #endif /* _LINUX_TRACE_CLOCK_H */ > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index b7d873b..4474f7d 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -263,8 +263,8 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait); > > /* trace_flags holds trace_options default values */ > unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | > - TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | > - TRACE_ITER_GRAPH_TIME; > + TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_LOCAL_CLK | > + TRACE_ITER_SLEEP_TIME | TRACE_ITER_GRAPH_TIME; > > /** > * trace_wake_up - wake up tasks waiting for trace input > @@ -324,6 +324,8 @@ static const char *trace_options[] = { > "context-info", > "latency-format", > "global-clock", > + "local-clock", > + "walltime-clock", > "sleep-time", > "graph-time", > NULL > @@ -1423,8 +1425,17 @@ static void print_lat_help_header(struct seq_file *m) > > static void print_func_help_header(struct seq_file *m) > { > - seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); > - seq_puts(m, "# | | | | |\n"); > + if (trace_flags & TRACE_ITER_WALLTIME_CLK) { > + seq_puts(m, "# TASK-PID CPU# " > + " TIMESTAMP FUNCTION\n"); > + seq_puts(m, "# | | | " > + " | |\n"); > + } else { > + seq_puts(m, "# TASK-PID CPU# " > + " TIMESTAMP FUNCTION\n"); > + seq_puts(m, "# | | | " > + " | |\n"); > + } > } > > > @@ -2151,30 +2162,42 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg) > > static void set_tracer_flags(unsigned int mask, int enabled) > { > + u64 (*clkfunc)(void) = NULL; > + > /* do nothing if flag is already set */ > if (!!(trace_flags & mask) == !!enabled) > return; > > - if (enabled) > - trace_flags |= mask; > - else > - trace_flags &= ~mask; > + if (mask == TRACE_ITER_GLOBAL_CLK) > + clkfunc = trace_clock_global; > + if (mask == TRACE_ITER_LOCAL_CLK) > + clkfunc = trace_clock_local; > + if (mask == TRACE_ITER_WALLTIME_CLK) > + clkfunc = trace_clock_walltime; > > - if (mask == TRACE_ITER_GLOBAL_CLK) { > - u64 (*func)(void); > + if (clkfunc) { > + if (!enabled) > + return;
If the user set a clock option file to 0, then it means he was expecting something, probably reset the default clock which is clock_local.
But what if the user set 0 to the local_clock...hmm..
| |