On Mon, Dec 20 2021, Jeff Hostetler via GitGitGadget wrote:
> From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
>
> Teach Trace2 "perf" and "event" formats to handle "timer" events for
> stopwatch timers. Update API documentation accordingly.
>
> In a future commit, stopwatch timers will be added to the Trace2 API
> and it will emit these "timer" events.
>
> Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
> ---
> Documentation/technical/api-trace2.txt | 25 +++++++++++++++-
> trace2/tr2_tgt.h | 25 ++++++++++++++++
> trace2/tr2_tgt_event.c | 40 +++++++++++++++++++++++++-
> trace2/tr2_tgt_normal.c | 1 +
> trace2/tr2_tgt_perf.c | 29 +++++++++++++++++++
> 5 files changed, 118 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
> index bb13ca3db8b..e6ed94ba814 100644
> --- a/Documentation/technical/api-trace2.txt
> +++ b/Documentation/technical/api-trace2.txt
> @@ -391,7 +391,7 @@ only present on the "start" and "atexit" events.
> {
> "event":"version",
> ...
> - "evt":"3", # EVENT format version
> + "evt":"4", # EVENT format version
> "exe":"2.20.1.155.g426c96fcdb" # git version
> }
FWIW this seems like a time not to bump the version per the proposed
approach in:
https://lore.kernel.org/git/211201.86zgpk9u3t.gmgdl@xxxxxxxxxxxxxxxxxxx/
Not directly related to this series, which just preserves the status
quo, but it would be nice to get feedback on that proposal from you.
> [...]
> + * Verison 1: original version
A typo of "Version".
> + * Version 2: added "too_many_files" event
> + * Version 3: added "child_ready" event
> + * Version 4: added "timer" event
> */
> -#define TR2_EVENT_VERSION "3"
> +#define TR2_EVENT_VERSION "4"
>
> /*
> * Region nesting limit for messages written to the event target.
> @@ -615,6 +620,38 @@ static void fn_data_json_fl(const char *file, int line,
> }
> }
>
> +static void fn_timer(uint64_t us_elapsed_absolute,
> + const char *thread_name,
> + const char *category,
> + const char *timer_name,
> + uint64_t interval_count,
> + uint64_t us_total_time,
> + uint64_t us_min_time,
> + uint64_t us_max_time)
> +{
> + const char *event_name = "timer";
> + struct json_writer jw = JSON_WRITER_INIT;
> + double t_abs = (double)us_elapsed_absolute / 1000000.0;
> +
nit: Odd placement of \n\n
> + double t_total = (double)us_total_time / 1000000.0;
> + double t_min = (double)us_min_time / 1000000.0;
> + double t_max = (double)us_max_time / 1000000.0;
Both for this...
> + jw_object_begin(&jw, 0);
> + event_fmt_prepare(event_name, __FILE__, __LINE__, NULL, &jw, thread_name);
> + jw_object_double(&jw, "t_abs", 6, t_abs);
> + jw_object_string(&jw, "name", timer_name);
> + jw_object_intmax(&jw, "count", interval_count);
> + jw_object_double(&jw, "t_total", 6, t_total);
> + jw_object_double(&jw, "t_min", 6, t_min);
> + jw_object_double(&jw, "t_max", 6, t_max);
[...]
> +static void fn_timer(uint64_t us_elapsed_absolute,
> + const char *thread_name,
> + const char *category,
> + const char *timer_name,
> + uint64_t interval_count,
> + uint64_t us_total_time,
> + uint64_t us_min_time,
> + uint64_t us_max_time)
> +{
> + const char *event_name = "timer";
> + struct strbuf buf_payload = STRBUF_INIT;
> +
> + double t_total = (double)us_total_time / 1000000.0;
> + double t_min = (double)us_min_time / 1000000.0;
> + double t_max = (double)us_max_time / 1000000.0;
> +
> + strbuf_addf(&buf_payload, "name:%s", timer_name);
> + strbuf_addf(&buf_payload, " count:%"PRIu64, interval_count);
> + strbuf_addf(&buf_payload, " total:%9.6f", t_total);
> + strbuf_addf(&buf_payload, " min:%9.6f", t_min);
> + strbuf_addf(&buf_payload, " max:%9.6f", t_max);
...and this, wouldn't it be better/more readable to retain the uint64_t
for the math, and just cast if needed when we're doing the formatting?
