From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [RESEND PATCH v7 2/4] Documentation, dt, arm64/arm: dt bindings for numa. Date: Fri, 18 Dec 2015 14:18:26 +0000 Message-ID: <20151218141826.GB30229@leverpostej> References: <1450413433-7467-1-git-send-email-gkulkarni@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1450413433-7467-1-git-send-email-gkulkarni@caviumnetworks.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Ganapatrao Kulkarni Cc: catalin.marinas@arm.com, Will.Deacon@arm.com, pawel.moll@arm.com, al.stone@linaro.org, Prasun.Kapoor@caviumnetworks.com, msalter@redhat.com, rfranz@cavium.com, lenb@kernel.org, devicetree@vger.kernel.org, steve.capper@linaro.org, arnd@arndb.de, ijc+devicetree@hellion.org.uk, marc.zyngier@arm.com, leif.lindholm@linaro.org, rrichter@cavium.com, grant.likely@linaro.org, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, ard.biesheuvel@linaro.org, rjw@rjwysocki.net, hanjun.guo@linaro.org, galak@codeaurora.org, gpkulkarni@gmail.com List-Id: devicetree@vger.kernel.org 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