From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,292c095d622af1d0 X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Received: by 10.68.195.165 with SMTP id if5mr921367pbc.1.1337064913667; Mon, 14 May 2012 23:55:13 -0700 (PDT) MIME-Version: 1.0 Path: pr3ni548pbb.0!nntp.google.com!news2.google.com!goblin2!goblin1!goblin.stu.neva.ru!news.tornevall.net!news.jacob-sparre.dk!munin.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: basic question on Ada tasks and running on different cores Date: Tue, 15 May 2012 01:55:01 -0500 Organization: Jacob Sparre Andersen Research & Innovation Message-ID: References: <30585369.219.1336470732142.JavaMail.geo-discussion-forums@ynbq3> <82d369u0nc.fsf@stephe-leake.org> NNTP-Posting-Host: static-69-95-181-76.mad.choiceone.net X-Trace: munin.nbi.dk 1337064907 26854 69.95.181.76 (15 May 2012 06:55:07 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Tue, 15 May 2012 06:55:07 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Date: 2012-05-15T01:55:01-05:00 List-Id: "Stephen Leake" wrote in message news:82d369u0nc.fsf@stephe-leake.org... > "Randy Brukardt" writes: > >> Secondly, I'm skeptical that any language attempting fine-grained >> parallelism can ever perform anywhere near as well as a language using >> coarse parallelism (like Ada) and deterministic sequential semantics for >> the >> rest. Any parallelism requires scheduling overhead, and that overhead is >> going to be a lot higher for the fine-grained case, simply because there >> is >> a lot more of it needed (even if it is conceptually simpler). > > Have you been following Parasail? > http://parasail-programming-language.blogspot.com/ > > Not fully implemented yet, but it sounds very interesting. A little bit, but I don't think even Tucker can do scheduling with no cost. (So far as I know, there is a significant penalty to running in the Parasail virtual machine, and I doubt that he'll be able to get rid of it.) Languages like this assume that it is OK to waste some significant fraction of the CPU in order to make it up on volume, er parallelism. As I said, I'm skeptical, but that doesn't mean that people shouldn't try -- and clearly, there are many applications where the performance isn't that critical or even where the added cost might actually provide some speed-up. Randy. Randy.