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Subject: Re: [hwloc-devel] stock HWLOC_XMLFILE? (was: hwloc support added in Grid Engine / Grid Scheduler)
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2011-04-18 13:15:23

Le 18/04/2011 19:00, Rayson Ho a écrit :
> However, I still get bug reports from people who have multi-socket AMD
> Magny-Cours servers. I am wondering if there are stock XML files
> available for download, esp. some HWLOC_XMLFILEs generated on
> multi-socket, multi-core (or even SMT) machines??

Here are 4 examples. The filename tells you how many sockets ("s"), numa
nodes ("n"), cores ("c") and ("t") each parent contains. You have an old
quad-socket dual-core HT (4s2c2t), a dual westmere with HT (2s6c2t), a
dual magny-cours (2s2n6c) and a quad-magny-cours (4s2n6c).

You can generate whatever you need manually. For instance:
    lstopo -i "socket:2 node:4 core:3 pu:2" foo.xml
creates a machine containing 2 sockets, with 4 numa node in each of
them, with 3 cores in each of them, and 2 threads in each core. Only the
last part ("pu:X", the number of PU/threads per core is needed).
Everything else is optional and you can do pretty much what you want.

> And the XML file mechanism turns out to be really useful!!

Yes many people under-estimate how cool this is. Not only for debugging,
but also to reload the same topology over and over much faster (you need
an additional flag in this case, to tell hwloc that your loading another
topology but it still corresponds the actual machine you're running on).