From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Andy Wingo Newsgroups: gmane.lisp.guile.devel Subject: Re: Whats' the proper senario of par-map? (Was Re: bug#13188: par-map causes VM stack overflow) Date: Mon, 01 Apr 2013 21:10:32 +0200 Message-ID: <87y5d2cbiv.fsf@pobox.com> References: <1355559152.27310.5.camel@Renee-desktop.suse> <87y5d8rclr.fsf@gnu.org> <1364439334.2730.41.camel@Renee-desktop.suse> <874nfwazc3.fsf@tines.lan> <1364524610.2730.48.camel@Renee-desktop.suse> <87d2uiah6h.fsf@tines.lan> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1364843452 23470 80.91.229.3 (1 Apr 2013 19:10:52 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 1 Apr 2013 19:10:52 +0000 (UTC) Cc: guile-devel@gnu.org To: Mark H Weaver Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Mon Apr 01 21:11:17 2013 Return-path: Envelope-to: guile-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1UMk8S-0001BT-A6 for guile-devel@m.gmane.org; Mon, 01 Apr 2013 21:11:16 +0200 Original-Received: from localhost ([::1]:33458 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UMk83-00089v-LF for guile-devel@m.gmane.org; Mon, 01 Apr 2013 15:10:51 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:53055) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UMk7s-00089c-1n for guile-devel@gnu.org; Mon, 01 Apr 2013 15:10:43 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UMk7o-00046g-PG for guile-devel@gnu.org; Mon, 01 Apr 2013 15:10:39 -0400 Original-Received: from a-pb-sasl-quonix.pobox.com ([208.72.237.25]:52211 helo=sasl.smtp.pobox.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UMk7o-00046a-L2 for guile-devel@gnu.org; Mon, 01 Apr 2013 15:10:36 -0400 Original-Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTP id F3CF1B46F; Mon, 1 Apr 2013 15:10:35 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=Jn3jk2KMJ5t9eSFtJubKQtBPUEU=; b=rFD1yv jS69DXdVd3Y4hEi37L8zkObg8Is53AH8f3hMRXf2XGcWlSB7FB0AFQYwAQKnT6em p/gMdylUFO2xc8u+veL4bzDo96mmJTGA4U8b4Lk6wJwyqJWLKjarKgtDLGI3+lov Ma8mhOGlTC5ktRQZnOAqIKrR2faur4/SgI41k= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=bNLhDFKfGi4D9+ZB/eHjG2BOSa5mmPVA 0SRBVeIzx0G6dChAFCdnaxveJldQW6x0qJHdbxOGrCF0vwNcdRYi0MCZFHaE7koa +dAI+bcjmipApq/hwAMh1NMkbirThdjgrB09Pqv4a1kDlMo/c4OWkxOW6HLTURqi 3IDnkpAuqyo= Original-Received: from a-pb-sasl-quonix.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTP id EB792B46D; Mon, 1 Apr 2013 15:10:35 -0400 (EDT) Original-Received: from badger (unknown [88.160.190.192]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTPSA id 60142B46C; Mon, 1 Apr 2013 15:10:35 -0400 (EDT) In-Reply-To: <87d2uiah6h.fsf@tines.lan> (Mark H. Weaver's message of "Fri, 29 Mar 2013 01:49:58 -0400") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.2 (gnu/linux) X-Pobox-Relay-ID: D4FE8370-9AFF-11E2-ABB7-D36F0E5B5709-02397024!a-pb-sasl-quonix.pobox.com X-detected-operating-system: by eggs.gnu.org: Solaris 10 X-Received-From: 208.72.237.25 X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:16096 Archived-At: On Fri 29 Mar 2013 06:49, Mark H Weaver writes: >> scheme@(guile-user)> ,time (define a (map (lambda (x) (expt x 5)) (iota >> 10000))) >> ;; 0.008019s real time, 0.007979s run time. 0.000000s spent in GC. >> scheme@(guile-user)> ,time (define a (par-map (lambda (x) (expt x 5)) >> (iota 10000))) >> ;; 6.596471s real time, 6.579375s run time. 1.513880s spent in GC. > > The timings above suggest that, on your machine, the overhead of > 'par-map' is in the neighborhood of 660 microseconds per thread (that's > the total run time divided by 10000 iterations). Per item, you mean? Anyway this seems like a really high overhead, and we shouldn't make too many excuses for it ;) Andy -- http://wingolog.org/