Re: [RFC PATCH] regmap: remove duplicate `type` field from `regcache_sync` trace event

[Mathieu Desnoyers <mathieu.desnoyers@efficios.com>]

Hi Philippe,

Some additional feedback:

The patch title could be changed to:

"tracing: Remove duplicate `type` field from regmap `regcache_sync` trace event"

to clarify that this belongs to tracing.

----- On Nov 23, 2020, at 11:15 AM, Philippe Duplessis-Guindon pduplessis@efficios.com wrote:

> I had an error saying that `regcache_sync` had 2 fields named `type` while using
> libtraceevent. This was the format of this event:

Please use the present rather than past when writing a commit message.

> 
>	$ sudo cat /sys/kernel/debug/tracing/events/regmap/regcache_sync/format
>	name: regcache_sync
>	ID: 1216
>	format:
>		field:unsigned short common_type;	offset:0;	size:2; signed:0;
>		field:unsigned char common_flags;	offset:2;	size:1; signed:0;
>		field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
>		field:int common_pid;	offset:4;	size:4;	signed:1;
> 
>		field:__data_loc char[] name;	offset:8;	size:4;	signed:1;
>		field:__data_loc char[] status;	offset:12;	size:4;	signed:1;
>		field:__data_loc char[] type;	offset:16;	size:4;	signed:1;
>		field:int type;    offset:20;    size:4;    signed:1;
> 
>	print fmt: "%s type=%s status=%s", __get_str(name), __get_str(type),
>	__get_str(status)
> 
> Erase the `int field` type, who was not assigned. This field was introduce by

who -> which

was introduce -> was introduced

Ideally you should use git blame to identify which commit introduced this issue.
e.g.:

git blame drivers/base/regmap/trace.h
[...]
593600890110c include/trace/events/regmap.h (Dimitris Papastamos 2011-09-19 14:34:04 +0100 134)                 __assign_str(status, status);
593600890110c include/trace/events/regmap.h (Dimitris Papastamos 2011-09-19 14:34:04 +0100 135)                 __assign_str(type, type);

commit 593600890110c02eb471cf844649dee213870416
Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Date:   Mon Sep 19 14:34:04 2011 +0100

    regmap: Add the regcache_sync trace event

This information can be added to the commit message as:

Fixes commit 593600890110c ("regmap: Add the regcache_sync trace event")

Thanks,

Mathieu

> mistake and this commit removes it.
> 
> This is the format of this event after the fix:
> 
>	$ sudo cat /sys/kernel/debug/tracing/events/regmap/regcache_sync/format
>	name: regcache_sync
>	ID: 1266
>	format:
>		field:unsigned short common_type;	offset:0;	size:2;	signed:0;
>		field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
>		field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
>		field:int common_pid;	offset:4;	size:4;	signed:1;
> 
>		field:__data_loc char[] name;	offset:8;	size:4;	signed:1;
>		field:__data_loc char[] status;	offset:12;	size:4;	signed:1;
>		field:__data_loc char[] type;	offset:16;	size:4;	signed:1;
> 
>	print fmt: "%s type=%s status=%s", __get_str(name), __get_str(type),
>	__get_str(status)
> 
> Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
> ---
> drivers/base/regmap/trace.h | 1 -
> 1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/base/regmap/trace.h b/drivers/base/regmap/trace.h
> index d4066fa079ab..9abee14df9ee 100644
> --- a/drivers/base/regmap/trace.h
> +++ b/drivers/base/regmap/trace.h
> @@ -126,7 +126,6 @@ TRACE_EVENT(regcache_sync,
> 		__string(       name,           regmap_name(map)	)
> 		__string(	status,		status			)
> 		__string(	type,		type			)
> -		__field(	int,		type			)
> 	),
> 
> 	TP_fast_assign(
> --
> 2.25.1

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com