From: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>
To: Sudeep Holla <sudeep.holla-5wv7dgnIgG8@public.gmane.org>
Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Jeremy Linton <jeremy.linton-5wv7dgnIgG8@public.gmane.org>,
Morten Rasmussen <morten.rasmussen-5wv7dgnIgG8@public.gmane.org>,
Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
Subject: Re: [RFC PATCH] Documentation: DT: arm: Add topology property to define package boundaries
Date: Thu, 8 Feb 2018 11:05:41 +0000 [thread overview]
Message-ID: <20180208110541.GB1179@e107981-ln.cambridge.arm.com> (raw)
In-Reply-To: <c9ab384b-1408-eccb-b417-af9a8a22119c-5wv7dgnIgG8@public.gmane.org>
On Mon, Jan 22, 2018 at 05:29:20PM +0000, Sudeep Holla wrote:
>
>
> On 22/01/18 17:15, 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-5wv7dgnIgG8@public.gmane.org>
> > Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > Cc: Sudeep Holla <sudeep.holla-5wv7dgnIgG8@public.gmane.org>
> > Cc: Jeremy Linton <jeremy.linton-5wv7dgnIgG8@public.gmane.org>
> > Cc: Morten Rasmussen <morten.rasmussen-5wv7dgnIgG8@public.gmane.org>
> > Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
> > ---
> > 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>
>
> IIUC, value type must be specified as boolean in this case.
That's what I thought too but according to DT specs v0.2, table 2.3 the
property value type is <empty>.
I do not mind changing it - whatever DT maintainers think is more
appropriate.
Thanks,
Lorenzo
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next prev parent reply other threads:[~2018-02-08 11:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-22 17:15 [RFC PATCH] Documentation: DT: arm: Add topology property to define package boundaries Lorenzo Pieralisi
[not found] ` <20180122171534.7681-1-lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>
2018-01-22 17:29 ` Sudeep Holla
[not found] ` <c9ab384b-1408-eccb-b417-af9a8a22119c-5wv7dgnIgG8@public.gmane.org>
2018-02-08 11:05 ` Lorenzo Pieralisi [this message]
2018-01-22 23:25 ` Jeremy Linton
[not found] ` <dcafd8bc-1c10-bdfa-e855-5d48cfe63381-5wv7dgnIgG8@public.gmane.org>
2018-01-23 10:35 ` Sudeep Holla
2018-01-23 4:45 ` Frank Rowand
2018-02-08 10:57 ` Lorenzo Pieralisi
[not found] ` <20180208105702.GA1179-4tUPXFaYRHv6sAKXYmQ0tx/iLCjYCKR+VpNB7YpNyf8@public.gmane.org>
2018-02-08 22:22 ` Frank Rowand
[not found] ` <d4ef76c3-fb4a-f879-44a8-7322ebde36ac-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-02-09 9:43 ` Lorenzo Pieralisi
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