From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: * X-Spam-Status: No, score=1.3 required=5.0 tests=AWL,MAILTO_TO_SPAM_ADDR, SPF_NEUTRAL autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from discorde.inria.fr (discorde.inria.fr [192.93.2.38]) by yquem.inria.fr (Postfix) with ESMTP id 7E97ABC0B for ; Thu, 18 Jan 2007 04:03:20 +0100 (CET) Received: from wr-out-0506.google.com (wr-out-0506.google.com [64.233.184.229]) by discorde.inria.fr (8.13.6/8.13.6) with ESMTP id l0I33J1e004984 for ; Thu, 18 Jan 2007 04:03:20 +0100 Received: by wr-out-0506.google.com with SMTP id i28so77632wra for ; Wed, 17 Jan 2007 19:03:17 -0800 (PST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=CDar/aox9D++oCITUsXOZ5INiPpPd+7wXy88wd1WuxykmUG5fJjY1mbXOppQaNXTNRyEOmPtBdG/lPNI96aWvHpnPUDntJfWr+EjVPuhiD4TM9rFXCyPqPzKItWACI4H48VGOrPKKZKJZdaS2rw94C0S9eJi/sAx/11hRypoDJ4= Received: by 10.78.172.20 with SMTP id u20mr363688hue.1169089395017; Wed, 17 Jan 2007 19:03:15 -0800 (PST) Received: by 10.78.159.17 with HTTP; Wed, 17 Jan 2007 19:03:14 -0800 (PST) Message-ID: Date: Thu, 18 Jan 2007 16:03:14 +1300 From: "Jonathan Roewen" To: "Edgar Friendly" Subject: Re: [Caml-list] Benchmarking different dispatch types Cc: "Nathaniel Gray" , "Caml List" In-Reply-To: <45AED8C8.3080808@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <45AED8C8.3080808@gmail.com> X-j-chkmail-Score: MSGID : 45AEE377.000 on discorde : j-chkmail score : X : 0/20 1 0.000 -> 1 X-Miltered: at discorde with ID 45AEE377.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; usr:01 usr:01 ocaml:01 ocamlfind:01 ocamlopt:01 -package:01 -inline:01 cmxa:01 cmxa:01 beginner's:01 ocaml:01 bug:01 edgar:98 16%:98 12%:98 >>From what I understand, anything other than a function is bound to be fairly slow in comparison. For closures, you first have to build the closure from the environment, and then invoke it; and methods require some sort of lookup. Functions, on the other hand, are fairly simply: it's just a call to a known address (putting aside passing the actual arguments to the function/method call). Sure, there may be some optimisations to be gained in some places, or a bit over-simplistic in other cases, but the basic premise is the same for supporting the overall view the numbers give (not so much the ratios) IMO. Jonathan On 1/18/07, Edgar Friendly wrote: > Nathaniel Gray wrote: > > > > Here's the output (on a PPC G4 1.25 GHz): > > > > ======== > > Latencies for 40000 iterations of function, method, closure, obj. closure: > > function: 0 WALL ( 0.00 usr + -0.00 sys = 0.00 CPU) @ > > 305343511.45/s (n=40000) > > (warning: too few iterations for a reliable count) > > method: 0 WALL ( 0.00 usr + -0.00 sys = 0.00 CPU) @ > > 27081922.82/s (n=40000) > > (warning: too few iterations for a reliable count) > > closure: 0 WALL ( 0.00 usr + 0.00 sys = 0.00 CPU) @ > > 30280090.84/s (n=40000) > > (warning: too few iterations for a reliable count) > > obj. closure: 0 WALL ( 0.00 usr + 0.00 sys = 0.00 CPU) @ > > 26058631.92/s (n=40000) > > (warning: too few iterations for a reliable count) > > Rate method obj. closure closure function > > method 25974026/s -- -5% -16% -90% > > obj. closure 27210884/s 5% -- -12% > > -89% > > closure 31007752/s 19% 14% -- -88% > > function 254777070/s 881% 836% 722% -- > > > > Interesting, but are they meaningful? The warnings from Benchmark are > > troubling, but I didn't have any immediate ideas on how to get rid of > > them. Any suggestions? > > > > Thanks, > > -n8 > > > > [1] http://ocaml-benchmark.sourceforge.net > > > > well, running only 40,000 iterations is way too low because timing > errors are going to get in the way of an accurate answer. On my > computer, I bumped the iterations up to max_int, and still the function > call was still taking less than one CPU second of time (which I guess is > the requirement for the warning to disappear). > > Here's my numbers from an Athlon XP-M 2000+ (1.53GHz), compiled with > ocaml 3.09.3, cmd. line: > $ ocamlfind ocamlopt -package "benchmark" -inline 0 unix.cmxa > benchmark.cmxa dispatch.ml > > > Latencies for 1073741823 iterations of function, method, closure, obj. > closure: > function: 0 WALL (-0.02 usr + -0.00 sys = -0.02 CPU) > (warning: too few iterations for a reliable count) > method: 15 WALL (11.34 usr + 0.49 sys = 11.83 CPU) @ 90764313.02/s > (n=1073741823) > closure: 4 WALL ( 2.60 usr + -0.60 sys = 2.00 CPU) @ 536870911.50/s > (n=1073741823) > obj. closure: 8 WALL ( 4.31 usr + 0.03 sys = 4.34 CPU) @ > 247405950.00/s (n=1073741823) > Rate function method obj. closure > closure > function -5.36871e+10/s -- -59250% -21800% > -10100% > method 90764313/s -100% -- -63% > -83% > obj. closure 247405950/s -100% 173% -- > -54% > closure 536870911/s -101% 491% 117% > -- > > Either function calls are just that stupidly efficient, or there's some > optimization still going on. I'm guessing the second. > > E. > > _______________________________________________ > Caml-list mailing list. Subscription management: > http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list > Archives: http://caml.inria.fr > Beginner's list: http://groups.yahoo.com/group/ocaml_beginners > Bug reports: http://caml.inria.fr/bin/caml-bugs >