On 01/22/18 09:15, Lorenzo Pieralisi wrote: > The current ARM DT topology description provides the operating system > with a topological view of the system that is based on leaf nodes > representing either cores or threads (in an SMT system) and a > hierarchical set of cluster nodes that creates a hierarchical topology > view of how those cores and threads are grouped. > > As opposed to the ACPI topology description ([1], PPTT table), this > hierarchical representation of clusters does not allow to describe what > topology level actually represents the physical package boundary, which > is a key piece of information to be used by an operating system to > optimize resource allocation and scheduling. > > Define an optional, backward compatible boolean property for cluster > nodes that, by reusing the ACPI nomenclature, add to the ARM DT > topological description a binding to define what cluster level > represents a physical package boundary. > > [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Cc: Sudeep Holla <sudeep.holla@xxxxxxx> > Cc: Jeremy Linton <jeremy.linton@xxxxxxx> > Cc: Morten Rasmussen <morten.rasmussen@xxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > --- > Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt > index de9eb0486630..8e78d76b0671 100644 > --- a/Documentation/devicetree/bindings/arm/topology.txt > +++ b/Documentation/devicetree/bindings/arm/topology.txt > @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: > The cluster node name must be "clusterN" as described in 2.1 above. > A cluster node can not be a leaf node. > > + Properties for cluster nodes: > + > + - physical-package > + Usage: optional > + Value type: <empty> > + Definition: if present the cluster node represents the > + boundary of a physical package, whether socketed > + or surface mounted. I don't know how to interpret this. Is the node with this property inside or outside the boundary? If I had to guess, I would guess inside. A few extra words to clarify this please. > + > A cluster node's child nodes must be: > > - one or more cluster nodes; or > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
