From owner-freebsd-current@FreeBSD.ORG Wed May 13 18:56:19 2015 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 88899B52; Wed, 13 May 2015 18:56:19 +0000 (UTC) Received: from relay.mailchannels.net (aso-006-i431.relay.mailchannels.net [23.91.64.112]) by mx1.freebsd.org (Postfix) with ESMTP id 528A6169F; Wed, 13 May 2015 18:56:17 +0000 (UTC) X-Sender-Id: duocircle|x-authuser|hippie Received: from smtp3.ore.mailhop.org (ip-10-237-13-110.us-west-2.compute.internal [10.237.13.110]) by relay.mailchannels.net (Postfix) with ESMTPA id 5B21A60DC4; Wed, 13 May 2015 18:47:18 +0000 (UTC) X-Sender-Id: duocircle|x-authuser|hippie Received: from smtp3.ore.mailhop.org (smtp3.ore.mailhop.org [10.83.15.107]) (using TLSv1 with cipher DHE-RSA-AES256-SHA) by 0.0.0.0:2500 (trex/5.4.8); Wed, 13 May 2015 18:47:19 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: duocircle|x-authuser|hippie X-MailChannels-Auth-Id: duocircle X-MC-Loop-Signature: 1431542838540:3629874207 X-MC-Ingress-Time: 1431542838539 Received: from c-73-34-117-227.hsd1.co.comcast.net ([73.34.117.227] helo=ilsoft.org) by smtp3.ore.mailhop.org with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.82) (envelope-from ) id 1Ysbgb-0002PV-NC; Wed, 13 May 2015 18:47:17 +0000 Received: from revolution.hippie.lan (revolution.hippie.lan [172.22.42.240]) by ilsoft.org (8.14.9/8.14.9) with ESMTP id t4DIlFcs004018; Wed, 13 May 2015 12:47:15 -0600 (MDT) (envelope-from ian@freebsd.org) X-Mail-Handler: DuoCircle Outbound SMTP X-Originating-IP: 73.34.117.227 X-Report-Abuse-To: abuse@duocircle.com (see https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information for abuse reporting information) X-MHO-User: U2FsdGVkX1+NSwqKEZSXtb8FJeesGARZ Message-ID: <1431542835.1221.30.camel@freebsd.org> Subject: Re: Increase BUFSIZ to 8192 From: Ian Lepore To: John-Mark Gurney Cc: Adrian Chadd , Hans Petter Selasky , David Chisnall , Poul-Henning Kamp , Baptiste Daroussin , "current@freebsd.org" Date: Wed, 13 May 2015 12:47:15 -0600 In-Reply-To: <20150513181347.GM37063@funkthat.com> References: <20150511230635.GA46991@ivaldir.etoilebsd.net> <20150512032307.GP37063@funkthat.com> <14994.1431412293@critter.freebsd.dk> <20150513080342.GE37063@funkthat.com> <55530CC3.1090204@selasky.org> <1431528249.1221.15.camel@freebsd.org> <20150513181347.GM37063@funkthat.com> Content-Type: text/plain; charset="us-ascii" X-Mailer: Evolution 3.12.10 FreeBSD GNOME Team Port Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-AuthUser: hippie X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 May 2015 18:56:19 -0000 On Wed, 2015-05-13 at 11:13 -0700, John-Mark Gurney wrote: > Adrian Chadd wrote this message on Wed, May 13, 2015 at 08:34 -0700: > > The reason I ask about "why is it faster?" is because for embedded-y > > things with low RAM we may not want that to happen due to memory > > constraints. However, we may actually want to do some form of > > autotuning on some platforms. > > If you're already running a program, the difference between 1k and > 8k isn't significant... I'll give you 64k can be significant for > embedded-y platforms... But this goes back to the, we need a global > knob saying I want low memory usage, and I am willing to pay for it > in performance... > It is NOT just a difference of 1K vs 8K. It's that much times however many BUFSIZ-sized things a program has allocated at once. It's where they are allocated. As I've already pointed out, BUFSIZ appears in the base code over 2000 times. Where is the analysis of the impact an 8x change is going to have on all those uses? -- Ian