Re: [lttng-dev] [PATCH 09/11] sched: export task_prio to GPL modules

On 12/20/11 03:08, Ingo Molnar wrote:
> 
> (Cc:-ing Arnaldo on this as well.)
> 
> * Mathieu Desnoyers <[email protected]> wrote:
> 

< snip >

> I think your concentration on ABIs is missing a very fundamental 
> property of instrumentation:
> 
>   the life-time and persistence of instrumentation data is 
>   typically very short ('days' is already an exception - typical 
>   is minutes, at most hours), and for that reason we havent been 
>   getting much pressure from users to maintain a perf.data ABI - 
>   but we are doing it nevertheless.
> 
> Instrumentation is fundamentally about the 'here and now' and so 
> it fundamentally differs from things like backup formats and 
> database formats. An ABI does not hurt and we are maintaining 
> it, but you are overrating its importance significantly.

Just to provide visibility to a different use case...

The life time of my data is typically weeks, months, or years
(though I am not likely to re-process year old raw data).

< snip >

-Frank