From owner-svn-src-head@FreeBSD.ORG Mon Nov 3 18:05:46 2008 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 43CB5106567D; Mon, 3 Nov 2008 18:05:46 +0000 (UTC) (envelope-from keramida@freebsd.org) Received: from igloo.linux.gr (igloo.linux.gr [62.1.205.36]) by mx1.freebsd.org (Postfix) with ESMTP id AEF7C8FC0C; Mon, 3 Nov 2008 18:05:45 +0000 (UTC) (envelope-from keramida@freebsd.org) Received: from kobe.laptop (adsl198-174.kln.forthnet.gr [79.103.11.174]) (authenticated bits=128) by igloo.linux.gr (8.14.3/8.14.3/Debian-5) with ESMTP id mA3I5XiU029678 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 3 Nov 2008 20:05:39 +0200 Received: from kobe.laptop (kobe.laptop [127.0.0.1]) by kobe.laptop (8.14.3/8.14.3) with ESMTP id mA3I5XQH052613; Mon, 3 Nov 2008 20:05:33 +0200 (EET) (envelope-from keramida@freebsd.org) Received: (from keramida@localhost) by kobe.laptop (8.14.3/8.14.3/Submit) id mA3I5VS3052612; Mon, 3 Nov 2008 20:05:31 +0200 (EET) (envelope-from keramida@freebsd.org) From: Giorgos Keramidas To: Peter Jeremy References: <200810301405.m9UE5wwZ053250@svn.freebsd.org> <877i7pdzva.fsf@kobe.laptop> <9bbcef730811021534gb114db9x16a2d6c9a3ecee8b@mail.gmail.com> <20081103075818.GK99398@server.vk2pj.dyndns.org> Date: Mon, 03 Nov 2008 20:05:31 +0200 In-Reply-To: <20081103075818.GK99398@server.vk2pj.dyndns.org> (Peter Jeremy's message of "Mon, 3 Nov 2008 18:58:18 +1100") Message-ID: <87y700it1w.fsf@kobe.laptop> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (berkeley-unix) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-MailScanner-ID: mA3I5XiU029678 X-Hellug-MailScanner: Found to be clean X-Hellug-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-4.099, required 5, autolearn=not spam, ALL_TRUSTED -1.80, AWL 0.30, BAYES_00 -2.60) X-Hellug-MailScanner-From: keramida@freebsd.org X-Spam-Status: No Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Ivan Voras Subject: Re: svn commit: r184471 - in head/bin: cat cp X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Nov 2008 18:05:46 -0000 On Mon, 3 Nov 2008 18:58:18 +1100, Peter Jeremy wrote: > On 2008-Nov-03 00:34:47 +0100, Ivan Voras wrote: >>2008/10/31 Giorgos Keramidas : >>The difference between the best and the worst is 247 context switches >>(total, not per second). >> >>> It looks like it's probably worth pushing the limit up to 8 MB when we >>> have lots of memory :) >> >>Yes, it's an improvement, but who will ever notice? :) > > Note that you will eventually hit a limit and start getting worse > performace: Once the buffer size exceeds the available free RAM > then cp/cat will start eating into inactive pages or (worse) active > pages for other processes. Yes, that's a possibility. Ivan is right that shaving 1-2 hundred more context _total_ context switches may be a small gain for the extra cost in buffer memory :)