On Thu, Feb 3, 2022 at 10:15 AM Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote: > > On Thu, 3 Feb 2022 08:59:44 -0800 > Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > > On Thu, Feb 3, 2022 at 1:41 AM Jonathan Cameron > > <Jonathan.Cameron@xxxxxxxxxx> wrote: > > > > > > On Wed, 2 Feb 2022 07:44:37 -0800 > > > Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > > > > > > On Wed, Feb 2, 2022 at 1:45 AM Jonathan Cameron > > > > <Jonathan.Cameron@xxxxxxxxxx> wrote: > > > > > > > > > > On Tue, 1 Feb 2022 15:57:10 -0800 > > > > > Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > > > > > > > > > > On Mon, Jan 31, 2022 at 10:41 AM Jonathan Cameron > > > > > > <Jonathan.Cameron@xxxxxxxxxx> wrote: > > > > > > > > > > > > > > On Sun, 23 Jan 2022 16:31:24 -0800 > > > > > > > Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > > > > > > > > > > > > > > While CXL memory targets will have their own memory target node, > > > > > > > > individual memory devices may be affinitized like other PCI devices. > > > > > > > > Emit that attribute for memdevs. > > > > > > > > > > > > > > > > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> > > > > > > > > > > > > > > Hmm. Is this just duplicating what we can get from > > > > > > > the PCI device? It feels a bit like overkill to have it here > > > > > > > as well. > > > > > > > > > > > > Not all cxl_memdevs are associated with PCI devices. > > > > > > > > > > Platform devices have numa nodes too... > > > > > > > > So what's the harm in having a numa_node attribute local to the memdev? > > > > > > > > > > I'm not really against, it just wanted to raise the question of > > > whether we want these to go further than the granularity at which > > > numa nodes can be assigned. > > > > What is the "granularity at which numa nodes can be assigned"? It > > sounds like you are referencing a standard / document, so maybe I > > missed something. Certainly Proximity Domains != Linux NUMA nodes so > > it's not ACPI. > > Sure, it's the fusion of a number of possible sources, one of which > is ACPI. If there is a reason why it differs to the parent device > (which can be ACPI, or can just be from a bunch of other places which > I'm sure will keep growing) then it definitely makes sense to expose > it at that level. > > > > > > Right now that at platform_device or > > > PCI EP (from ACPI anyway). Sure the value might come from higher > > > up a hierarchy but at least in theory it can be assigned to > > > individual devices. > > > > > > This is pushing that description beyond that point so is worth discussing. > > > > To me, any device that presents a driver interface can declare its CPU > > affinity with a numa_node leaf attribute. Once you start walking the > > device tree to infer the node from parent information you also need to > > be worried about whether the Linux device topology follows the NUMA > > topology. The leaf attribute removes that ambiguity. > I'll go with 'maybe'... > > Either way I'm fine with this change, just wanted to bring attention to > the duplication as it wasn't totally clear to me it was a good idea. If the bar to upstream something was when it was totally clear it was a good idea... I'd have a lot less patches to send. > > FWIW > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Appreciate the discussion.
