Re: [PATCH 2/9] perf/core: Add PERF_SAMPLE_CGROUP feature

From: Namhyung Kim
Date: Sun Sep 08 2019 - 09:28:49 EST


Hi Tejun,

On Thu, Sep 05, 2019 at 09:56:55AM -0700, Tejun Heo wrote:
> Hello, Namhyung.
>
> On Tue, Sep 03, 2019 at 10:13:08AM +0800, Namhyung Kim wrote:
> > So is my understanding below correct?
> >
> > * currently kernfs ino+gen is different than inode's ino+gen
>
> They're the same. It's just that cgroup has other less useful IDs
> too.

Ah, ok.

>
> > * but it'd be better to make them same
> > * so move (generic?) inode's ino+gen logic to cgroup
> > * and kernfs node use the same logic (and number)
> > * so perf sampling code (NMI) just access kernfs node
> > * and userspace can use file handle for comparison
>
> The rest, yes, pretty much.

Thanks for the clarification. I'll take a look at it.

Thanks
Namhyung