From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754925AbYIAEIt (ORCPT ); Mon, 1 Sep 2008 00:08:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751182AbYIAEIi (ORCPT ); Mon, 1 Sep 2008 00:08:38 -0400 Received: from turing-police.cc.vt.edu ([128.173.14.107]:40552 "EHLO turing-police.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750987AbYIAEIg (ORCPT ); Mon, 1 Sep 2008 00:08:36 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: David Miller Cc: rick.jones2@hp.com, jmalicki@metacarta.com, andi@firstfloor.org, johnpol@2ka.mipt.ru, dada1@cosmosbay.com, denys@visp.net.lb, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, juhlenko@akamai.com, sammy@sammy.net Subject: Re: loaded router, excessive getnstimeofday in oprofile In-Reply-To: Your message of "Sun, 31 Aug 2008 20:51:45 PDT." <20080831.205145.225080276.davem@davemloft.net> From: Valdis.Kletnieks@vt.edu References: <21915755.1327801219904892242.JavaMail.root@ouachita> <48B6E7D0.5070307@hp.com> <20031.1220236756@turing-police.cc.vt.edu> <20080831.205145.225080276.davem@davemloft.net> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1220242094_3529P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Mon, 01 Sep 2008 00:08:14 -0400 Message-ID: <6720.1220242094@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1220242094_3529P Content-Type: text/plain; charset=us-ascii On Sun, 31 Aug 2008 20:51:45 PDT, David Miller said: > Many trades are made programaticcally using formulas and computer > algorithms in response to market activity and other trades of the > same security. > > There is no typing involved :) Still the same issue - the time delay in getting the ticker tape values back, making the decision, and launching the transaction are *way* bigger than the packet queueing order. Think - trading a few billion shares a day, if that ticker is even 5 seconds behind, *that* is a much bigger issue than what order the transactions happen in... > If the financial folks say they need this stuff, then unless we're > prepared to become experts in financial markets and how the IT stuff > for them are designed and run, we might as well just trust them on > this one. The toughest part of systems analysis is getting the user to shut up about what they say they need long enough for you to find out what it is they are actually trying to do. Quite frankly, unless somebody *IS* planning to become an expert on how the IT stuff for them are designed and run, we *should not* be doing any code changes that we don't understand, just because they say so and we should trust them... --==_Exmh_1220242094_3529P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFIu2qucC3lWbTT17ARAjxJAJ0ZfkmllygrI6OHbfwiffyUUcRdeACfYtjn r5t5NmUR4CWzJ4A+tBY9+PY= =9cER -----END PGP SIGNATURE----- --==_Exmh_1220242094_3529P--