On Mon, Oct 05, 2020 at 09:16:13AM +0000, Zidenberg, Tsahi wrote: > > > On 18/09/2020, 16:29, "Robin Murphy" <robin.murphy@xxxxxxx> wrote: > > Here's an update with some very minor cleanup tweaks, plus a proposal > > for some more in-depth debug information. Given that nobody seems to > > have any significant complaints about the interface, I assume we're all > > happy to merge the basic driver as-is and fix anything later if needed. > > > > Robin. > > Agree with merging the driver as-is. > Tested both the updated driver and the debugfs on Graviton2 (ACPI). > Both map and initial numbers seem right. > > Tested-by: Tsahi Zidenberg <tsahee@xxxxxxxxxx> > > May I offer a small addition to the documentation? > Something along these lines: > > --- a/Documentation/admin-guide/perf/arm-cmn.rst > +++ b/Documentation/admin-guide/perf/arm-cmn.rst > @@ -41,8 +41,14 @@ specified by "occupid". > > By default each event provides an aggregate count over all nodes of the > given type. To target a specific node, "bynodeid" must be set to 1 and > -"nodeid" to the appropriate value derived from the CMN configuration > -(as defined in the "Node ID Mapping" section of the TRM). > +"nodeid" to the appropriate value derived from the CMN configuration. > + > +The CMN map is available in /sys/kernel/debug/arm-cmn/map. > +A nodeid could be calculated with this formulae: > + node-id = d | (p << 2) | (y << 3) | (x << (3 + xybits)) > +where: > + x,y,p,d are node location as can be seen in the map > + xybits is 2 for meshes <= 2*2, and 3 otherwise. I already queued the driver, but if you send this as a stand-alone patch (on top of the arm64 for-next/perf branch) then I'm happy to take it. Thanks, Will > Watchpoints > ----------- >
