On 25/05/2010 21:02, Wheeler, Kyle Bruce wrote: > Hello, > > I don't see anything in hwloc for determining "distance" between objects in > the hierarchy. Is there something I'm missing? > > Obviously, distance doesn't make sense between all object types, and begs the > question "what units?". However, it's something that is supported in some > sense on several systems (liblgrp/libnuma/tmc), and it'd be nice to know it > exists in hwloc. >
Distances is something planned for 1.1. Ticket https://svn.open-mpi.org/trac/hwloc/ticket/32 is about it. hwloc already gathers distances from Linux sysfs (from the ACPI SLIT table) and Solaris to group NUMA nodes accordingly. We need to sort the matrix in the logical order (instead of OS order) and expose it to the application. And we need to clarify what we want to support exactly (extend the NUMA distance to a distance between other objects? what if we ever get some incomplete distance matrix?). What units must be well documented too, right. If you have comments/ideas to add on the ticket, let us know (or get an account and comment there :)). Brice
