Re: [PATCH v1] thermal/core: change mm alloc method to avoid kernel warning

[Junwen Wu]

From: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>

On 19/04/2022 15:54, Zhang Rui wrote:
> CC Viresh.
> 
> On Tue, 2022-04-19 at 11:14 +0200, Daniel Lezcano wrote:
>> On 19/04/2022 10:48, Zhang Rui wrote:
>>> large
>>>
>>> IMO, unless we can fix both places, I'd suggest we skip allocating
>>> and
>>> creating the broken trans_table attr. Like a prototype patch below
>>
>> Why not create a thermal debugfs with real useful information and
>> get
>> rid of this broken code ?
> 
> The idea looks good to me.

>What about doing a percentile approach of the state indexes changes 
>instead of a raw matrix full of zeros ? So we show the most significant 
>transitions, perhaps something like:
>
>99%:	7->6	6->7
>98%:	6->5	5->6
>95%:	5->4	4->5
>90%:	7->5	5->7
>80%:	6->4	4->6
>70%:	7->1	7->2
>50%:	...	...

>total:	123456	124573


>And another statistics file containing some timings information like the 
>total duration in mitigation, and the duration in the most significant 
>states above?

Viresh, Zhang Rui,  Daniel,sorry for the delay indeed ,the trans_table is always full of zero,
I introduce 'show_state' node(tunnable by user,default set as max_states/2) ,thus only show show_state'th  trans count
to the max trans count change stats. in this way trans_table_show's buffer always less than PAGE_SIZE
I create a patch v2
like this:
/sys/class/thermal/cooling_device0/stats # cat trans_table
 From  :    Index_change
state 0:      ->1( 1)      ->2( 2)      ->7( 1)
state 1:      ->0( 1)      ->2( 1)
state 2:      ->0( 2)      ->1( 1)

here is the patch: