On Feb 28, 2014, at 12:32 AM, Brice Goglin <brice.gog...@inria.fr> wrote:
> Le 28/02/2014 02:48, Ralph Castain a écrit : >> Remember, hwloc doesn't actually "sense" hardware - it just parses files in >> the /proc area. So if something is garbled in those files, hwloc will report >> errors. Doesn't mean anything is wrong with the hardware at all. > > For the record, that's not really true: > > hwloc looks at /sys (and a bit /proc files), but it also uses cpuid > instructions. 90% of the times, the former is better because the kernel > already took care of cleaning up the hardware mess and reporting > useful/correct info in /proc and /sys. Sometimes the kernel is too old > and it misses some hardware quirks (like L1i sharing on Gus' machine) > causing /sys files to be incompatible. Fair enough - but how do you know when to probe the BIOS and when to trust what is in the file? > > In the end, the vast majority of problems come from buggy BIOS, and > these cause both cpuid and kernel to report invalid info. Aside of > upgrading the BIOS, the only solution there is to replace the topology > with a correct XML one. > > Brice > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
