Subject: Re: [PATCH] trace2: increment event format version

From: Junio C Hamano <[email-masked]>
Date: Thu, 11 Nov 2021 15:03:10 -0800

Josh Steadmon <[email-masked]> writes:

> In 64bc752 (trace2: add trace2_child_ready() to report on background
> children, 2021-09-20), we added a new "child_ready" event. In
> Documentation/technical/api-trace2.txt, we promise that adding a new
> event type will result in incrementing the trace2 event format version
> number, but this was not done. Correct this in code & docs.
>
> Signed-off-by: Josh Steadmon <[email-masked]>
> ---
>  Documentation/technical/api-trace2.txt | 4 ++--
>  trace2/tr2_tgt_event.c                 | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)

Hmph, it seems to me that this is better done before the release,
or am I mistaken?

>
> diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
> index ef7fe02a8f..bb13ca3db8 100644
> --- a/Documentation/technical/api-trace2.txt
> +++ b/Documentation/technical/api-trace2.txt
> @@ -128,7 +128,7 @@ yields
>  
>  ------------
>  $ cat ~/log.event
> -{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"2","exe":"2.20.1.155.g426c96fcdb"}
> +{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"3","exe":"2.20.1.155.g426c96fcdb"}
>  {"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
>  {"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
>  {"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
> @@ -391,7 +391,7 @@ only present on the "start" and "atexit" events.
>  {
>  	"event":"version",
>  	...
> -	"evt":"2",		       # EVENT format version
> +	"evt":"3",		       # EVENT format version
>  	"exe":"2.20.1.155.g426c96fcdb" # git version
>  }
>  ------------
> diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
> index 70cfc2f77c..3a0014417c 100644
> --- a/trace2/tr2_tgt_event.c
> +++ b/trace2/tr2_tgt_event.c
> @@ -20,7 +20,7 @@ static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0, 0 };
>   * a new field to an existing event, do not require an increment to the EVENT
>   * format version.
>   */
> -#define TR2_EVENT_VERSION "2"
> +#define TR2_EVENT_VERSION "3"
>  
>  /*
>   * Region nesting limit for messages written to the event target.
>
> base-commit: e9e5ba39a78c8f5057262d49e261b42a8660d5b9