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* [PATCH] ring-buffer: fix kernel-doc format to avoid a warning
@ 2025-10-17  7:07 Randy Dunlap
  2025-10-17  9:08 ` Steven Rostedt
  0 siblings, 1 reply; 3+ messages in thread
From: Randy Dunlap @ 2025-10-17  7:07 UTC (permalink / raw)
  To: linux-kernel
  Cc: Randy Dunlap, Lai Jiangshan, Steven Rostedt, Masami Hiramatsu,
	Mathieu Desnoyers, linux-trace-kernel

Format the kernel-doc for RINGBUF_TYPE_DATA_TYPE_LEN_MAX correctly
to prevent a kernel-doc warning:

Warning: include/linux/ring_buffer.h:61 Enum value
 'RINGBUF_TYPE_DATA_TYPE_LEN_MAX' not described in enum 'ring_buffer_type'

Fixes: 334d4169a659 ("ring_buffer: compressed event header")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
---
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: linux-trace-kernel@vger.kernel.org
---
 include/linux/ring_buffer.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20251016.orig/include/linux/ring_buffer.h
+++ linux-next-20251016/include/linux/ring_buffer.h
@@ -43,7 +43,7 @@ struct ring_buffer_event {
  *				 array[0] = top (28 .. 59) bits
  *				 size = 8 bytes
  *
- * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
+ * @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
  *				Data record
  *				 If type_len is zero:
  *				  array[0] holds the actual length

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] ring-buffer: fix kernel-doc format to avoid a warning
  2025-10-17  7:07 [PATCH] ring-buffer: fix kernel-doc format to avoid a warning Randy Dunlap
@ 2025-10-17  9:08 ` Steven Rostedt
  2025-10-17 19:11   ` Randy Dunlap
  0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2025-10-17  9:08 UTC (permalink / raw)
  To: Randy Dunlap
  Cc: linux-kernel, Lai Jiangshan, Masami Hiramatsu, Mathieu Desnoyers,
	linux-trace-kernel

On Fri, 17 Oct 2025 00:07:53 -0700
Randy Dunlap <rdunlap@infradead.org> wrote:

> Format the kernel-doc for RINGBUF_TYPE_DATA_TYPE_LEN_MAX correctly
> to prevent a kernel-doc warning:
> 
> Warning: include/linux/ring_buffer.h:61 Enum value
>  'RINGBUF_TYPE_DATA_TYPE_LEN_MAX' not described in enum 'ring_buffer_type'

Then this needs to be updated differently, because that "<=" is stating
what happens when the value is <= RINGBUF_TYPE_DATA_TYPE_LEN_MAX.

It wasn't random characters.

Basically, the enum describes the event type.

enum ring_buffer_type {
        RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28,
        RINGBUF_TYPE_PADDING,
        RINGBUF_TYPE_TIME_EXTEND,
        RINGBUF_TYPE_TIME_STAMP,
};

When the type is > 28 it is either a padding, time-extend or
time-stamp. But if it is less than or equal to
RINGBUF_TYPE_DATA_TYPE_LEN_MAX then it is the length of a data event.

Perhaps we should have it be:

 * 0:
 *                              Data record
 *                                array[0] holds the actual length
 *                                array[1..(length+3)/4] holds data
 *                                size = 4 + length (bytes)
 *
 * 1 - @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
 *                              Data record
 *                                length = type_len << 2
 *                                array[0..(length+3)/4-1] holds data
 *                                size = 4 + length (bytes)

  ?

This data is more important that making kerneldoc work.

-- Steve


> 
> Fixes: 334d4169a659 ("ring_buffer: compressed event header")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> ---
> Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: linux-trace-kernel@vger.kernel.org
> ---
>  include/linux/ring_buffer.h |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- linux-next-20251016.orig/include/linux/ring_buffer.h
> +++ linux-next-20251016/include/linux/ring_buffer.h
> @@ -43,7 +43,7 @@ struct ring_buffer_event {
>   *				 array[0] = top (28 .. 59) bits
>   *				 size = 8 bytes
>   *
> - * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
> + * @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
>   *				Data record
>   *				 If type_len is zero:
>   *				  array[0] holds the actual length


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] ring-buffer: fix kernel-doc format to avoid a warning
  2025-10-17  9:08 ` Steven Rostedt
@ 2025-10-17 19:11   ` Randy Dunlap
  0 siblings, 0 replies; 3+ messages in thread
From: Randy Dunlap @ 2025-10-17 19:11 UTC (permalink / raw)
  To: Steven Rostedt
  Cc: linux-kernel, Lai Jiangshan, Masami Hiramatsu, Mathieu Desnoyers,
	linux-trace-kernel



On 10/17/25 2:08 AM, Steven Rostedt wrote:
> On Fri, 17 Oct 2025 00:07:53 -0700
> Randy Dunlap <rdunlap@infradead.org> wrote:
> 
>> Format the kernel-doc for RINGBUF_TYPE_DATA_TYPE_LEN_MAX correctly
>> to prevent a kernel-doc warning:
>>
>> Warning: include/linux/ring_buffer.h:61 Enum value
>>  'RINGBUF_TYPE_DATA_TYPE_LEN_MAX' not described in enum 'ring_buffer_type'
> 
> Then this needs to be updated differently, because that "<=" is stating
> what happens when the value is <= RINGBUF_TYPE_DATA_TYPE_LEN_MAX.
> 
> It wasn't random characters.
> 
> Basically, the enum describes the event type.
> 
> enum ring_buffer_type {
>         RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28,
>         RINGBUF_TYPE_PADDING,
>         RINGBUF_TYPE_TIME_EXTEND,
>         RINGBUF_TYPE_TIME_STAMP,
> };
> 
> When the type is > 28 it is either a padding, time-extend or
> time-stamp. But if it is less than or equal to
> RINGBUF_TYPE_DATA_TYPE_LEN_MAX then it is the length of a data event.
> 
> Perhaps we should have it be:
> 
>  * 0:
>  *                              Data record
>  *                                array[0] holds the actual length
>  *                                array[1..(length+3)/4] holds data
>  *                                size = 4 + length (bytes)
>  *
>  * 1 - @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
>  *                              Data record
>  *                                length = type_len << 2
>  *                                array[0..(length+3)/4-1] holds data
>  *                                size = 4 + length (bytes)
> 
>   ?
> 
> This data is more important that making kerneldoc work.

For sure it is. Thanks for the explanation.
I'll see if I can come up with an alternative - or not.

> 
> 
>>
>> Fixes: 334d4169a659 ("ring_buffer: compressed event header")
>> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
>> ---
>> Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
>> Cc: Steven Rostedt <rostedt@goodmis.org>
>> Cc: Masami Hiramatsu <mhiramat@kernel.org>
>> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
>> Cc: linux-trace-kernel@vger.kernel.org
>> ---
>>  include/linux/ring_buffer.h |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> --- linux-next-20251016.orig/include/linux/ring_buffer.h
>> +++ linux-next-20251016/include/linux/ring_buffer.h
>> @@ -43,7 +43,7 @@ struct ring_buffer_event {
>>   *				 array[0] = top (28 .. 59) bits
>>   *				 size = 8 bytes
>>   *
>> - * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
>> + * @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
>>   *				Data record
>>   *				 If type_len is zero:
>>   *				  array[0] holds the actual length
> 

-- 
~Randy


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2025-10-17 19:11 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2025-10-17  7:07 [PATCH] ring-buffer: fix kernel-doc format to avoid a warning Randy Dunlap
2025-10-17  9:08 ` Steven Rostedt
2025-10-17 19:11   ` Randy Dunlap

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