Re: [PATCH v11 8/8] perf: ARM DynamIQ Shared Unit PMU support

[Saravana Kannan]

On 02/23/2018 03:35 AM, Mark Rutland wrote:
> On Thu, Feb 22, 2018 at 12:38:39PM -0800, Saravana Kannan wrote:
> > On 02/22/2018 03:33 AM, Mark Rutland wrote:
> > > On Wed, Feb 21, 2018 at 06:32:46PM -0800, Saravana Kannan wrote:
> > > > I'm not exactly sure if we can add entries to perf_type_id. If that's
> > > > allowed maybe we need to add something line PERF_TYPE_DSU and use that?
> > > >
> > > > Or if that's not allowed then would it be better to offset the DSU PMU
> > > > events by some number (say 0x1000) and then delete the event type check or
> > > > pass PERF_TYPE_RAW to perf_pmu_register()?
> > >
> > > As above, neither of these should be necessary.
> >
> > For the userspace interface. How about the kernel interface though?
> > perf_event_create_kernel_counter() takes attr.type as an input. But there's
> > no way to look up the DSU PMU's "type".
>
> There is no lookup mechanism currently.
>
> I take it you want to use DSU events from a kernel module?

Yes

> It would be possible to have a simlar name -> type lookup mechanism
> kernel-side, if necessary.

Yeah, this is what I was thinking once you explained how user space 
handles this. Just wanted to hear it from this thread. I can submit a patch.

Thanks,
Saravana

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