From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Linas Vepstas Newsgroups: gmane.lisp.guile.user Subject: Re: GC thread performance Date: Fri, 1 Dec 2017 13:49:35 -0600 Message-ID: References: <192F0231-DBB4-40D4-B3D6-0BAAB254CC59@telia.com> <87mv37z4q0.fsf@elektro.pacujo.net> <848C0138-B297-42C2-B45A-562176B88025@telia.com> Reply-To: linasvepstas@gmail.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1512159606 26416 195.159.176.226 (1 Dec 2017 20:20:06 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 1 Dec 2017 20:20:06 +0000 (UTC) Cc: Guile User To: =?UTF-8?Q?Hans_=C3=85berg?= Original-X-From: guile-user-bounces+guile-user=m.gmane.org@gnu.org Fri Dec 01 21:20:02 2017 Return-path: Envelope-to: guile-user@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eKrmz-0006Xi-Vq for guile-user@m.gmane.org; Fri, 01 Dec 2017 21:20:02 +0100 Original-Received: from localhost ([::1]:60665 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eKrn7-0002NS-1N for guile-user@m.gmane.org; Fri, 01 Dec 2017 15:20:09 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:56151) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eKrJv-0000qO-3u for guile-user@gnu.org; Fri, 01 Dec 2017 14:50:00 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eKrJu-0004Xb-5U for guile-user@gnu.org; Fri, 01 Dec 2017 14:49:59 -0500 Original-Received: from mail-lf0-x22e.google.com ([2a00:1450:4010:c07::22e]:37194) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eKrJt-0004Wj-RW for guile-user@gnu.org; Fri, 01 Dec 2017 14:49:58 -0500 Original-Received: by mail-lf0-x22e.google.com with SMTP id a12so12929900lfe.4 for ; Fri, 01 Dec 2017 11:49:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:reply-to:in-reply-to:references:from:date:message-id :subject:to:cc; bh=urHkHyy597WZJtB8/iTVYUveJIpTacwE/HOGHJe/Dl8=; b=g43JKHkoluI1yq6M/UYYBZaPL4hbFVWV7h/BjyM4bYoq7QupMVxFQ9Vmhzgjy+G49V Kkl8+sSEStjYpfwbp6iMY1FMHYO/b2UzcXfSdglvlq2BN3COC8TBiy5GLk1RogopeotI 6x0FEQY8zIkCxcuDpxfnTGCEn7+WjRQbSC0ROfruC0gJ3Yu6ZaWAdPUfa2i2D+2Q+IEL Eqjhlf8Kil/BCQH6cBtZuPOMgxeHZVH3HJAoSSx1/qt0oesDjrpASNASTCEisynvYBA2 HxXLonEdV8PuViMqSDYhH1gxDGm4V9Eh0Px4ZY9CuDK4jrNxMafqaQQKYD713Ub8Vi9l +bIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:reply-to:in-reply-to:references :from:date:message-id:subject:to:cc; bh=urHkHyy597WZJtB8/iTVYUveJIpTacwE/HOGHJe/Dl8=; b=k64jSmYRhDH4tq1UkBcrTlUArNmfUAiE4JIBJrKYovBziNN2seO2RPBtcUQGKv6baJ 65inoWXDATPWzEdIOeptWcBrvV9rx8q17z1J32bvQ5I0zelhYAv1fbHTiH2msvVWOiqF fWOf6jA0LNiO4bET57a0nEYWb2SSPsF9csViV1L322iO29+By4OnW0A/lnU1cwvhgWUU KV3ZyOXWs+887mFziLNWmYSzupvgxKmqY1JtqhWNEBv4vpatlBaa0D/0nolfHIkzsOQZ TQTz9cAEZ3TdgaYelqVNRqc384e2VAZPAxz7ESbFDSv624n8NSnED9F6/3ZKNRf/gd+t TDQw== X-Gm-Message-State: AJaThX7eJNuVZjbjs3c7QrafUDmsEY2HcgZLnRnoJ2VIkhtPp2UD5+nE bJMYEpqhN340pB4RE+Omu3kh2ey7uD4axrbNMvc= X-Google-Smtp-Source: AGs4zMZMAy53T5OAGvG7WW7o1foRwFuWEeojsy+HwnMm2edFzFrLdkVCoqlKGWJ9iX3TCGbA1oc4pKAME3jHbEGCQxk= X-Received: by 10.46.17.153 with SMTP id 25mr5623995ljr.36.1512157796149; Fri, 01 Dec 2017 11:49:56 -0800 (PST) Original-Received: by 10.25.149.13 with HTTP; Fri, 1 Dec 2017 11:49:35 -0800 (PST) In-Reply-To: <848C0138-B297-42C2-B45A-562176B88025@telia.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:4010:c07::22e X-Content-Filtered-By: Mailman/MimeDel 2.1.21 X-BeenThere: guile-user@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: General Guile related discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-user-bounces+guile-user=m.gmane.org@gnu.org Original-Sender: "guile-user" Xref: news.gmane.org gmane.lisp.guile.user:14306 Archived-At: On Mon, Nov 27, 2017 at 5:44 PM, Hans =C3=85berg wrote= : > > > > On 28 Nov 2017, at 00:23, Marko Rauhamaa wrote: > > > > Hans =C3=85berg : > >> I saw overhead also for the small allocations, 20-30% maybe. This is > >> in a program that makes a lot of allocations relative other > >> computations. So that made me wonder about Guile. > I cannot speak to GC, but I freuqently encounter situations in guile where using the parallel constructs e.g. par-for-each, end up running slower than the single-threaded version. For example, using 2 or 3 threads, I get a 2x and 3x speedup, great, but using 4x gives a slowdown, often 10x slower than single-threaded. I try to make sure that the insides of the loop are large and long-running, so that the cost of creating and scheduling threads is inconsequential. I have not attempted to determine the cause of this, but basically, that entire subsystem needs a careful review and measurement. --linas --=20 *"The problem is not that artificial intelligence will get too smart and take over the world," computer scientist Pedro Domingos writes, "the problem is that it's too stupid and already has." *