From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Keith Wright Newsgroups: gmane.lisp.guile.user Subject: Re: map-par slower than map Date: Sun, 23 Oct 2022 23:56:58 -0400 Message-ID: <878rl5kh6d.fsf@fcs22.keithdiane.us> References: <87860c1f-e590-8e16-e031-dedc99cd3864@posteo.de> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="4127"; mail-complaints-to="usenet@ciao.gmane.io" Cc: damien.mattei@gmail.com, guile-user@gnu.org To: Zelphir Kaltstahl Original-X-From: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Mon Oct 24 08:09:57 2022 Return-path: Envelope-to: guile-user@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1omqer-0000qK-6k for guile-user@m.gmane-mx.org; Mon, 24 Oct 2022 08:09:57 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1omoaw-0002X4-JG; Sun, 23 Oct 2022 23:57:46 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1omoaf-0002Ti-Pv for guile-user@gnu.org; Sun, 23 Oct 2022 23:57:31 -0400 Original-Received: from dsl.keithdiane.us ([66.92.74.188]) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1omoad-0001Zl-8v for guile-user@gnu.org; Sun, 23 Oct 2022 23:57:28 -0400 Original-Received: from fcs22.keithdiane.us (fcs22.keithdiane.us [192.168.1.121]) by fcs19.keithdiane.us (Postfix) with ESMTP id A9BAB218375; Sun, 23 Oct 2022 23:56:58 -0400 (EDT) In-Reply-To: <87860c1f-e590-8e16-e031-dedc99cd3864@posteo.de> (message from Zelphir Kaltstahl on Sun, 23 Oct 2022 23:18:58 +0000) Received-SPF: pass client-ip=66.92.74.188; envelope-from=kwright@keithdiane.us; helo=dsl.keithdiane.us X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: guile-user@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Guile related discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: "guile-user" Errors-To: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.lisp.guile.user:18676 Archived-At: Zelphir Kaltstahl writes: > Of course,if you have global state and do not have a synchronization > construct for accessing the hash table, I would expect things to > go wrong at some point, with non-reproducible results. Indeed. > I do not think that futures are to blame here, > or parallel map in that case. Are futures to blame? Do you blame the plus sign for this wrong equation: 4+5=20? My teachers blamed me for that sort of thing. > With a synchronization construct, some kind of mutex, > your bottle neck might just become that mutex. But why make it parallel at all? Unless you have some serious parallel hardware you will just be wasting time in the scheduler when you could be computing the answer. In other news --- there are many kinds of people on this mailing list. I wonder what percentage are the kind that needs page-long disjunctive normal form expressions in their mail boxes? Not me. -- Keith PS: For page-long boolean expression, they are nice. But why?