Re: [PATCH] perf/core: move all of the pmu devices into their own location

Ian Rogers
2025-02-04T18:17:29Z

On Mon, Feb 3, 2025 at 11:05 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Mon, Feb 03, 2025 at 11:44:13AM -0800, Ian Rogers wrote:
> > On Mon, Feb 3, 2025 at 11:25 AM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
[snip]
> > > Note, if you all don't like "pmu_bus" for the name, that's fine, please
> > > let me know and I can rename it to something else, but it should be
> > > something to get these objects out of the root sysfs directory.
> >
> > Excuse my ignorance, does the event_source bus already provide a
> > similar solution?
> > ```
> > $ ls /sys/bus/event_source/devices
> > breakpoint i915 msr uncore_arb uncore_cbox_3
> > uncore_cbox_7 uprobe
> > cpu intel_bts power uncore_cbox_0 uncore_cbox_4 uncore_clock
> > cstate_core intel_pt software uncore_cbox_1 uncore_cbox_5
> > uncore_imc_free_running_0
> > cstate_pkg kprobe tracepoint uncore_cbox_2 uncore_cbox_6
> > uncore_imc_free_running_1
> > $ ls /sys/devices
> > breakpoint intel_pt platform uncore_arb uncore_cbox_5
> > uprobe
> > cpu isa pnp0 uncore_cbox_0 uncore_cbox_6
> > virtual
> > cstate_core kprobe power uncore_cbox_1 uncore_cbox_7
> > cstate_pkg LNXSYSTM:00 software uncore_cbox_2 uncore_clock
> > i915 msr system uncore_cbox_3 uncore_imc_free_running_0
> > intel_bts pci0000:00 tracepoint uncore_cbox_4 uncore_imc_free_running_1
> > ```
>
> Those are the exact same device structures :)
>
> Look at /sys/bus/event_source/devices/ those are symlinks back to
> /sys/devices. In other words, that's the exact same structures, and
> the mess in /sys/devices/ with these event devices is what I am trying
> to clean up.

Thanks! Again my ignorance, why do we need pmu_bus? Could the symlinks
in event_source be the actual devices? Perhaps for temporary
compatibility some symlinks could be placed in /sys/devices?

Thanks,
Ian