On 3/31/21 6:58 AM, Michael Ellerman wrote: > David Gibson <da...@gibson.dropbear.id.au> writes: >> On Mon, Mar 29, 2021 at 03:32:37PM -0300, Daniel Henrique Barboza wrote: > ... >> >>> We assign ibm,chip-id=0x0 to CPUs 0-3, but CPUs 2-3 are located in a >>> different NUMA node than 0-1. This would mean that the same socket >>> would belong to different NUMA nodes at the same time. >> >> Right... and I'm still not seeing why that's a problem. AFAICT that's >> a possible, if unexpected, situation under real hardware - though >> maybe not for POWER9 specifically. > > I think I agree. > >>> I believe this is what Cedric wants to be addressed. Given that the >>> property is called after the OPAL property ibm,chip-id, the kernel >>> expects that the property will have the same semantics as in OPAL. >> >> Even on powernv, I'm not clear why chip-id is tied into the NUMA >> configuration, rather than getting all the NUMA info from >> associativity properties. > > AFAIK we don't use chip-id for anything related to NUMA, if we do I'd > consider that a bug.
Since PAPR only has NUMA nodes, is the use of chip-id in XIVE PAPR considered as a bug ? I would say so. > We do use it for topology_physical_package_id(), but that's almost > completely unused. In that case, I think it should be fine to return -1 like under PowerVM. Thanks, C.
