[RESEND PATCH v7 2/4] Documentation, dt, arm64/arm: dt bindings for numa.

Mark Rutland mark.rutland at arm.com
Fri Dec 18 06:18:26 PST 2015


Hi,

> +==============================================================================
> +2 - numa-node-id
> +==============================================================================
> +
> +For the purpose of identification, each NUMA node is associated with a unique
> +token known as a node id. For the purpose of this binding
> +a node id is a 32-bit integer.
> +
> +A device node is associated with a NUMA node by the presence of a
> +numa-node-id property which contains the node id of the device.
> +
> +Example:
> +	/* numa node 0 */
> +	numa-node-id = <0>;
> +
> +	/* numa node 1 */
> +	numa-node-id = <1>;
> +
> +==============================================================================
> +3 - distance-map
> +==============================================================================
> +
> +The device tree node distance-map describes the relative
> +distance(memory latency) between all numa nodes.
> +
> +- compatible : Should at least contain "numa-distance-map-v1".

Thank you for updating these per my request.

The fact that these have changed since the late posting [1] means that
this is a new version of the patch rather than a resend. Please update
the PATCHvX number when changes are made.

You also need to update the driver for the new compatible string, so a
new version of that is required.

> +- distance-matrix
> +  This property defines a matrix to describe the relative distances
> +  between all numa nodes.
> +  It is represented as a list of node pairs and their relative distance.
> +
> +  Note:
> +	1. Each entry represents distance from first node to second node.
> +	The distance are equal in either direction.
> +	2. The distance from a node to self(local distance) is represented
> +	with value 10 and all inter node distance should be represented with
> +	value greater than 10.
> +	3. distance-matrix shold have entries in lexicographical ascending
> +	order of nodes.
> +	4. There must be only one Device node distance-map and must reside in the root node.

I am still concerned that the local distance of 10 is completely
arbitrary.

Please:

* Add a new local-distance property to the distance-map node allowing a
  uniform local distance to be described, and require this property to
  be present.

* Update the driver to account for that and the compatible string
  change.

* Send a complete PATCHv8 (or PATCHv$X where X > 7) series with a proper
  changelog.

Thanks,
Mark.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-November/385826.html



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