On Mon, 16 Dec 2013 13:10:52 +0900
Yoshihiro YUNOMAE <yoshihiro.yunomae...@hitachi.com> wrote:
> Hi Ian,
>
> (2013/12/13 8:30), Ian Webster wrote:
> > This change adds a --clock option to trace-cmd record. It simply writes
> > trace_clock on debugfs. Examples of valid choices on most systems are:
> > local,
> > global, counter, and any other choice compatible with ftrace.
>
> Nice work!
> Please see my following comments.
Hmm, I was waiting for a reply back with an update against these
comments and never saw one. I eventually forgot about this patch :-(
I went to add it now, and noticed that I already added a -C option for
trace-clock which also works for instances.
Sorry about forgetting about this patch (just found it buried in my
inbox).
I'll be releasing 2.6 soon, with a bunch of new updates.
-- Steve
>
> > This complements Yoshihiro Yunomae's change 8c9867c (trace-cmd: Add support
> > for
> > extracting trace_clock in report).
> >
> > Signed-off-by: Ian Webster <i...@planetaryresources.com>
> >
> > ---
> > Changes per Steven's comments:
> > * add missing const
> > * preserve tab whitespace
> >
> > Documentation/trace-cmd-record.1.txt | 5 +++++
> > trace-record.c | 19 +++++++++++++++++++
> > trace-usage.c | 1 +
> > 3 files changed, 25 insertions(+)
> >
> > diff --git a/Documentation/trace-cmd-record.1.txt
> > b/Documentation/trace-cmd-record.1.txt
> > index 832a257..5e83454 100644
> > --- a/Documentation/trace-cmd-record.1.txt
> > +++ b/Documentation/trace-cmd-record.1.txt
> > @@ -240,6 +240,11 @@ OPTIONS
> > timestamp to gettimeofday which will allow wall time output from the
> > timestamps reading the created 'trace.dat' file.
> >
> > +*--clock* 'clock_name'::
> > + When an event is recorded into the ring buffer, a timestamp is added.
> > This
> > + stamp comes from the specified clock. Ftrace uses the "local" clock by
> > + default. Other common clocks include: global, counter, uptime, perf,
> > x86-tsc.
> > +
> > EXAMPLES
> > --------
> >
> > diff --git a/trace-record.c b/trace-record.c
> > index 0199627..2143080 100644
> > --- a/trace-record.c
> > +++ b/trace-record.c
> > @@ -399,6 +399,20 @@ static int set_ftrace(int set, int use_proc)
> > return 0;
> > }
> >
> > +static void set_trace_clock(const char *clock_choice)
> > +{
> > + FILE *fp;
> > + char *path;
> > +
> > + path = tracecmd_get_tracing_file("trace_clock");
> > + fp = fopen(path, "w");
> > + if (!fp)
> > + die("writing to '%s'", path);
> > + tracecmd_put_tracing_file(path);
> > + fwrite(clock_choice, 1, strlen(clock_choice), fp);
>
> Please add an error check for fwrite(). If clock_choice is invalid,
> trace-cmd would better output the error report and die.
>
> > + fclose(fp);
> > +}
> > +
> > static char *
> > get_instance_file(struct buffer_instance *instance, const char *file)
> > {
> > @@ -2279,6 +2293,7 @@ static void record_all_events(void)
> > }
> >
> > enum {
> > + OPT_clock = 252,
> > OPT_nosplice = 253,
> > OPT_funcstack = 254,
> > OPT_date = 255,
> > @@ -2351,6 +2366,7 @@ void trace_record (int argc, char **argv)
> > {"func-stack", no_argument, NULL, OPT_funcstack},
> > {"nosplice", no_argument, NULL, OPT_nosplice},
> > {"help", no_argument, NULL, '?'},
> > + {"clock", required_argument, NULL, OPT_clock},
> > {NULL, 0, NULL, 0}
> > };
> >
> > @@ -2530,6 +2546,9 @@ void trace_record (int argc, char **argv)
> > case OPT_nosplice:
> > recorder_flags |= TRACECMD_RECORD_NOSPLICE;
> > break;
> > + case OPT_clock:
> > + set_trace_clock(optarg);
> > + break;
>
> This implementation does not support multiple buffers.
> trace_clock had better be changed after sub-buffers are created, I
> think.
>
> Example:
> trace-cmd record -e sched --clock local -B foo -e block --clock x86-tsc
>
> Thanks,
> Yoshihiro YUNOMAE
>
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