From mboxrd@z Thu Jan 1 00:00:00 1970 From: colin ngam Date: Wed, 11 May 2005 16:05:02 +0000 Subject: Re: [RFC] pcibus_to_node implementation for ia64 Message-Id: <42822D2E.3020708@sgi.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Jesse Barnes wrote: >On Wednesday, May 11, 2005 8:44 am, colin ngam wrote: > > >>Fine line here .. a valid node id is always returned and that nodeid >>is a vaild node id for addressing the bus/devices and may be the only >>node id you can use to address these buses and devices, except when >>the IO Brick is dual ported. It is valid with respect to addressing >>the bus/devices but may not be "valid" with respect to "having >>Memory" or "having cpus". Depends on what you expect :-) Depends on >>how you want to use it :-) >> >> > >But not valid in the sense that you can pass it to any of the kernel >routines that say they take a 'node' argument. IMO, that's a bug in >the implementation of I/O and memoryless nodes in sn2. As Jack and I >discussed last year at OLS (he convinced me of this), a node is any >combination of memory, CPUs, and/or I/O. If I/O nodes (or nodes w/o >memory generally) are special cased, we're breaking that assumption, >making things harder for every caller and user of nodes. > > I think we are in agreement here. They should not be special case - but caller and users of node id has to be cognizant that a node does not necessary mean it has cpus, memory or both. Thanks. colin