> > one piece of information that Ganglia collects for a node is the > "number of CPUs", originally meaning "physical CPUs".
Ok I was afraid of that. > With the > introduction of HT and multi-core things are a bit more complex now. We > have decided that HT sibblings do not qualify as "real" CPUs, while > multi-cores do. I think that decision is a mistake, and is probably based on experiences with the first generation of HT capable Pentium 4 processors. The original p4 HT to a large degree suffered from a too small cache that now was shared. SMT in general isn't per se all that different in performance than dual core, at least not on a fundamental level, it's all a matter of how many resources each thread has on average. With dual core sharing the cache for example, that already is part HT. Putting the "boundary" at HT-but-not-dual-core is going to be highly artificial and while it may work for the current hardware, in general it's not a good way of separating things (just look at the PowerPC processors, those are highly SMT as well), and I suspect that your distinction is just going to break all the time over the next 10 years ;) Or even today on the current "large cache" P4 processors with HT it already breaks. (just those tend to be the expensive models so more rare) I would strongly urge you to reconsider this decision; if you want to show "sockets" that sounds reasonable, or even if you want to do it on the "bus sharing" level (FSB/HT), but HT.. just sounds wrong. -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
