Re: [PATCH v1 0/2] perf stat: Support --all-kernel and --all-user

[Jin, Yao]

On 10/1/2019 10:17 AM, Andi Kleen wrote:
> > > I think it's useful. Makes it easy to do kernel/user break downs.
> > > perf record should support the same.
> >
> > Don't we have this already with:
> >
> > [root@quaco ~]# perf stat -e cycles:u,instructions:u,cycles:k,instructions:k -a -- sleep 1
>
> This only works for simple cases. Try it for --topdown or multiple -M metrics.
>
> -Andi

Hi Arnaldo, Jiri,

We think it should be very useful if --all-user / --all-kernel can be 
specified together, so that we can get a break down between user and 
kernel easily.

But yes, the patches for supporting this new semantics is much 
complicated than the patch which just follows original perf-record 
behavior. I fully understand this concern.

So if this new semantics can be accepted, that would be very good. But 
if you think the new semantics is too complicated, I'm also fine for 
posting a new patch which just follows the perf-record behavior.

Thanks
Jin Yao