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,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,da39df064d0b18d7 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!postnews.google.com!c2g2000yqi.googlegroups.com!not-for-mail From: jonathan Newsgroups: comp.lang.ada Subject: Re: GNAT's stack checking in Ubuntu 9.04 (and Shootout regex-dna) Date: Tue, 11 Aug 2009 14:19:38 -0700 (PDT) Organization: http://groups.google.com Message-ID: <56853fb1-fc2a-4757-9959-6142b9121c4e@c2g2000yqi.googlegroups.com> References: <4a776a94$0$31878$9b4e6d93@newsspool3.arcor-online.net> <4a7f1fc5$0$31344$9b4e6d93@newsspool4.arcor-online.net> <9adb4985-582c-4cbf-906c-3afa7dcd31f6@g1g2000vbr.googlegroups.com> <4a80ae6e$0$31877$9b4e6d93@newsspool3.arcor-online.net> <4564d943-9a6a-4112-9ae2-f379b8654669@18g2000yqa.googlegroups.com> NNTP-Posting-Host: 143.117.23.233 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: posting.google.com 1250025578 4307 127.0.0.1 (11 Aug 2009 21:19:38 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Tue, 11 Aug 2009 21:19:38 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: c2g2000yqi.googlegroups.com; posting-host=143.117.23.233; posting-account=Jzt5lQoAAAB4PhTgRLOPGuTLd_K1LY-C User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.12) Gecko/2009072220 Iceweasel/3.0.6 (Debian-3.0.6-1),gzip(gfe),gzip(gfe) Xref: g2news2.google.com comp.lang.ada:7683 Date: 2009-08-11T14:19:38-07:00 List-Id: On Aug 11, 9:02=A0pm, jonathan wrote: > On Aug 11, 12:34=A0am, Georg Bauhaus > bug.bauh...@maps.futureapps.de> wrote: > > Does regexdna-multi.ada work on your system? > > > On a dual core system it seems to be shortening > > the running time by almost a third. Final report (this time I mean it): I tested regexdna-multi.ada on an older dual-core machine I have access to. It is almost exactly half as fast (per core) as the quad-core I used previously. Main question: is 3 tasks better than 2 at exploiting parallelism. On the 8-core machine, 9 tasks was optimal. On the dual-core the answer is yes, but the benefit is much smaller here: 1 task running time: 59 sec 2 task running time: 37.5 sec 3 task running time: 35 sec where number of tasks is set by Max_CPUs. Jonathan