From owner-freebsd-hackers@FreeBSD.ORG Fri Jan 28 00:04:31 2011 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7F6381065670 for ; Fri, 28 Jan 2011 00:04:31 +0000 (UTC) (envelope-from kabaev@gmail.com) Received: from mail-qw0-f54.google.com (mail-qw0-f54.google.com [209.85.216.54]) by mx1.freebsd.org (Postfix) with ESMTP id 23D308FC15 for ; Fri, 28 Jan 2011 00:04:30 +0000 (UTC) Received: by qwj9 with SMTP id 9so2739757qwj.13 for ; Thu, 27 Jan 2011 16:04:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:date:from:to:cc:subject:message-id:in-reply-to :references:x-mailer:mime-version:content-type; bh=oo77vy/ilRDZUS+1sCsAW1nLgDgDP7mn2Mj5ync1ApA=; b=CNVlsN4h1eSdzNITVK0LPH+g4K866rmyoRidAy+GCwELvqFDES2UgaLLD0ESNafMHd t/LhFcPmIT00caaxYX4okLv9heupeM+EyU2LBXFeXLbMb/r5gErDxjGT31/qCqFYps/b rFuKIkDqisHRu29CmBGoIG0ULJnMvK+gixFDk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type; b=Fp1KbL/T5j+ESgzvcUgF3XBm56XhPcaiqLLdYQQ2GR3jcYaMunEciWmx/2/yObRbNf ekIb3tsH+suY4wojpIigl89aA82jyt76ZnycfrscwdYibyGeV8OL4gP48Hft7dMXKhCG L9mGlMM7/4rRXC9MK8mkByeSZXh154knpRNuE= Received: by 10.224.19.203 with SMTP id c11mr2274316qab.170.1296173070384; Thu, 27 Jan 2011 16:04:30 -0800 (PST) Received: from kan.dnsalias.net (c-24-63-226-98.hsd1.ma.comcast.net [24.63.226.98]) by mx.google.com with ESMTPS id nb15sm12214094qcb.38.2011.01.27.16.04.28 (version=SSLv3 cipher=RC4-MD5); Thu, 27 Jan 2011 16:04:29 -0800 (PST) Date: Thu, 27 Jan 2011 19:04:23 -0500 From: Alexander Kabaev To: Joerg Sonnenberger Message-ID: <20110127190423.785cb2d3@kan.dnsalias.net> In-Reply-To: <20110127234737.GA31603@britannica.bec.de> References: <201101271305.21510.naylor.b.david@gmail.com> <20110127203126.GN2518@deviant.kiev.zoral.com.ua> <1296161448.20060.40.camel@dt.vicor.com> <20110127205907.GP2518@deviant.kiev.zoral.com.ua> <1296162754.20060.42.camel@dt.vicor.com> <20110127213536.GR2518@deviant.kiev.zoral.com.ua> <1296165538.20060.43.camel@dt.vicor.com> <20110127182418.77c53c60@kan.dnsalias.net> <20110127234737.GA31603@britannica.bec.de> X-Mailer: Claws Mail 3.7.8 (GTK+ 2.22.1; amd64-portbld-freebsd9.0) Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/rkOlWEZaVxTAWFpFqlO2mmx"; protocol="application/pgp-signature" Cc: freebsd-hackers@freebsd.org Subject: Re: rtld optimizations X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Jan 2011 00:04:31 -0000 --Sig_/rkOlWEZaVxTAWFpFqlO2mmx Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 28 Jan 2011 00:47:37 +0100 Joerg Sonnenberger wrote: > On Thu, Jan 27, 2011 at 06:24:18PM -0500, Alexander Kabaev wrote: > > For starters, the number of libraries given binary is linked too is > > completely and utterly irrelevant :) The change NetBSD guys claims > > to revolutionize his application startup times only applies to > > programs that dlopen (read - load dynamically) libraries with long > > largely identical dependency chains and calls dlsym on them many, > > many thousand times. I do not think you will find any real app out > > there that fits this description close enough to actually > > demonstrate the effect of the change that is distinguishable from > > the statistical noise. Pressing ^C certainly not precise enough for > > that. >=20 > (1) The program itself needs to have a large enough number of linked > libraries. That is wrong, of course. symlook_needed is only called when dlsym(, ) is called and the number of objects on main and global DAGS is very much an irrelevant detail hereirrelevant here. > (2) The program needs to dlopen() modules. Yep. > (3) The program needs to search for missing symbols often enough. > ... by means of explicit dlsym() call. =20 > From memory, the real world example that fulfilled all three cases was > Evolution. (1) and (2) are pretty typical though. >=20 Never claimed otherwise. It is just ones with nested trees deep enough to matter is what in very short supply. I would be very interested in seeing the Evolution benchmarked, but I dount very much than even Evolution will manage to break through statistical noise. --=20 Alexander Kabaev --Sig_/rkOlWEZaVxTAWFpFqlO2mmx Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (FreeBSD) iD8DBQFNQggMQ6z1jMm+XZYRAoyYAKCeGHhlVjj4thRtrzfL6Pq68zz96wCg2suV /0BQGbO16Ms3/q/kXqq/NL4= =0/Zp -----END PGP SIGNATURE----- --Sig_/rkOlWEZaVxTAWFpFqlO2mmx--