Re: perf group read for inherited events

[Andi Kleen]

On Tue, May 30, 2017 at 11:45:12AM +0200, Peter Zijlstra wrote:
> > Or is the simple patch below good enough?
> 
> The below seems to be the correct thing. It is rather unfortunate that
> this would break/significantly change existing semantics :/

The "existing semantics" as in ignoring the PERF_SAMPLE_READ in sample_type,
even though it wasn't implemented? It seems reasonable to me.

If you really worry about it could drop a printk_once in and see if it
triggers anywhere (and if yes drop the if completely)

The patch looks good to me. Please consider adding it.
I have some patches to use this in perf stat, will submit later.

-Andi