[PATCH] of: introduce event tracepoints for dynamic device_node lifecyle

Frank Rowand frowand.list at gmail.com
Thu Apr 20 20:44:32 AEST 2017


On 04/19/17 19:37, Frank Rowand wrote:
> On 04/19/17 11:45, Tyrel Datwyler wrote:
>> On 04/18/2017 07:49 PM, Steven Rostedt wrote:
>>> On Tue, 18 Apr 2017 18:42:32 -0700
>>> Frank Rowand <frowand.list at gmail.com> wrote:
>>>
>>>> And of course the other issue with using tracepoints is the extra space
>>>> required to hold the tracepoint info.  With the pr_debug() approach, the
>>>> space usage can be easily removed for a production kernel via a config
>>>> option.
>>>
>>> Now if you are saying you want to be able to enable debugging without
>>> the tracing infrastructure I would agree. As the tracing infrastructure
>>> is large. But I'm working on shrinking it more.
>>
>> The primary consumers of OF_DYNAMIC seem to be pseries and powernv where
>> we are generally going to see the trace infrastructure enabled by
>> default in production.
> 
> Another primary consumer will be overlays for ARM expansion boards.  Still
> a work in progress.

And dynamic configuration for the FPGA folks.


> -Frank
> 
>>
>> -Tyrel
>>
>>>
>>>>
>>>> Tracepoints are wonderful technology, but not always the proper tool to
>>>> use for debug info.
>>>
>>> But if you are going to have tracing enabled regardless, adding a few
>>> more tracepoints isn't going to make the difference.
>>>
>>> -- Steve
>>>
>>>>
>>>>> If Rob wants to convert printk() style data to trace data (and I can't
>>>>> convince him otherwise) then I will have further comments on this specific
>>>>> patch.
>>>>>
>>
>> .
>>
> 
> .
> 



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