Amdahl strikes again! I knew this lunch was too tasty to be free. I just thought of another analogy. When I think of something highly concurrent and scalable on the JVM, I think of web request handlers, which effectively use no memory-sharing for domain-specific work, at all, unless there is some in-memory application state, but in general they shift the problem to a database. When the bookkeeping overhead doesn't dominate, they appear to be highly concurrent.
Shared-memory a wall of abstraction, multi-core cpus don't work this way at the bottom level, so writing programs this way can only go so far. On Sun, Apr 28, 2013 at 11:22 AM, Manuel Paccagnella < manuel.paccagne...@gmail.com> wrote: > Ok, for everyone that is interested: > this<http://www.meetup.com/Functional-Programming-Connoisseurs/messages/boards/thread/30946382>thread > on meetup clarified things a bit for me and probably it's a good > summary on the specific case that Lee found. > > > Il giorno domenica 28 aprile 2013 17:07:04 UTC+2, Lee ha scritto: > >> >> On Apr 28, 2013, at 10:57 AM, Manuel Paccagnella wrote: >> > >> > This is an interesting perspective. Are you saying that currently >> Clojure doesn't offer adequate tools to take full advantage of parallel >> execution on multi-core machines? >> >> I am speaking only from my own experience, and only relative to my own >> case. But I've been unable to get reasonable speedups for my system, which >> I think should be an excellent candidate for multi-core speedups. And while >> I'm not an expert on JVM/Clojure performance I solicited and received >> advice from people on this list who I think are, and I'm still unable to >> get reasonable speedups -- maybe a couple of X but maybe not even that, on >> machines with core-counts up to 48. It may have to do with the kinds of >> tasks I'm running (lots of sequence manipulation and memory consumption, >> etc.), but for whatever reason I am still unable to get Clojure's >> oft-touted multi-core benefits. >> >> -Lee >> >> -- > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
