...and, suddenly, the high-core-count Opterons show us what we wanted and hoped for. If I increase that range statement to 100 and run it on the 48-core node, it takes 50 seconds (before it took 50 minutes), while the FX-8350 takes 3:31.89 and the 3770K takes 3:48.95. Thanks Marshall! I think you may have just saved us outrageous quantities of time, though Lee isn't convinced that we know exactly what's going on with clojush yet, I don't think. We haven't looked at it yet though.... I'm sure we will soon enough!
On Tue, Dec 11, 2012 at 2:57 PM, Wm. Josiah Erikson <wmjos...@gmail.com>wrote: > And, interestingly enough, suddenly the AMD FX-8350 beats the Intel Core > i7 3770K, when before it was very very much not so. So for some reason, > this bug was tickled more dramatically on AMD multicore processors than on > Intel ones. > > > On Tue, Dec 11, 2012 at 2:54 PM, Wm. Josiah Erikson <wmjos...@gmail.com>wrote: > >> OK WOW. You hit the nail on the head. It's "reverse" being called in a >> pmap that does it. When I redefine my own version of reverse (I totally >> cheated and just stole this) like this: >> >> (defn reverse-recursively [coll] >> (loop [[r & more :as all] (seq coll) >> acc '()] >> (if all >> (recur more (cons r acc)) >> acc))) >> >> >> >> I speed it up from, get this, 4:32 to 0:25. Yeah. >> >> In case anybody's curious, pmap and pmapall show identical performance in >> this case. >> >> Wow. >> >> -Josiah >> >> >> On Tue, Dec 11, 2012 at 1:06 PM, Marshall Bockrath-Vandegrift < >> llas...@gmail.com> wrote: >> >>> Lee Spector <lspec...@hampshire.edu> writes: >>> >>> > If the application does lots of "list processing" but does so with a >>> > mix of Clojure list and sequence manipulation functions, then one >>> > would have to write private, list/cons-only versions of all of these >>> > things? That is -- overstating it a bit, to be sure, but perhaps not >>> > entirely unfairly -- re-implement Clojure's Lisp? >>> >>> I just did a quick look over clojure/core.clj, and `reverse` is the only >>> function which stood out to me as hitting the most pathological case. >>> Every other `conj` loop over a user-provided datastructure is `conj`ing >>> into an explicit non-list/`Cons` type. >>> >>> So I think if you replace your calls to `reverse` and any `conj` loops >>> you have in your own code, you should see a perfectly reasonable >>> speedup. >>> >>> -Marshall >>> >>> -- >>> 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 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
