John Hearns wrote: > I'm surprised this has not been flagged up yet. Shamelessly passed on > from Slashdot: > http://www.gcn.com/online/vol1_no1/47765-1.html
John, Thanks for posting. I just read it. <unsolicited opinion> The problems the researchers cite are nothing new. Those issues have been around, and written about, for years the only difference is that the processors are now on the same die. Regarding the issue handling interrupts and how that can affect performance is discussed in this paper, which determined that in multiprocessors systems, it's best to let one processor do all the interrupt handling (and nothing else) http://hpc.pnl.gov/people/fabrizio/papers/sc03_noise.pdf The other problem they mention, when data one processor needs is in another processor's cache, and how that affects performance is nothing new, either. That's why we have processor affinity. I learned about that in my computer architecture class years ago - before multi-core processors existed. </unsolicited opinion> The above is based on the GCN article, not the actual paper it refers to. I haven't read all 12 pages of it yet, but I did skim through it. It's interesting to note that the research was conducted only on the Intel Architecture. They mention that the AMD NUMA architecture is more complicated and that they hope to do future research on it. Not including the AMDs in this research lame. Showing the difference in performance between architectures - *that* would be meaningful information that we could all use. But I guess that leaves the authors an opportunity to publish an additional paper on the same topic, so they can list two publications on their CVs instead of one. -- Prentice _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
