Hi Brice,

By the way, lstopo shows distance information, but it does not change it
depending on -l/-p. We may want to fix this.

Thanks for the hint, I din't know it.

Actually, Linux only uses the number of hops on one specific MIPS
architecture (SGI IP27 Origin 200/2000). In other cases, it uses the
cpu-to-memory latency (usually reported by ACPI or so).

Well, this is interesting. numactl --hardware shows the number of hops, regarding to the information from that private BZ. Where does hwloc takes the distance information? Is it stored with

hwloc-gather-topology

script? If yes, could me send me the output of hwloc-gather-topology for some NUMA box? I don't have access to any NUMA running a recent version of kernel.

> On some systems number of hops does not represent memory bandwidth. I
> have reported this in BZ 655041
>
> https://bugzilla.redhat.com/show_bug.cgi?id=655041

This bug is private unfortunately.

> In any case I believe that hwloc-report-instances would be useful
> utility. Please let me know your opinion.

Agreed.

OK, I will try to implement it as time permits.

Thanks

Jirka