From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 17 Sep 2002 22:10:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 17 Sep 2002 22:10:54 -0400 Received: from pizda.ninka.net ([216.101.162.242]:646 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Tue, 17 Sep 2002 22:10:53 -0400 Date: Tue, 17 Sep 2002 19:06:41 -0700 (PDT) Message-Id: <20020917.190641.84134530.davem@redhat.com> To: jgarzik@mandrakesoft.com Cc: akpm@digeo.com, manfred@colorfullife.com, netdev@oss.sgi.com, linux-kernel@vger.kernel.org Subject: Re: Info: NAPI performance at "low" loads From: "David S. Miller" In-Reply-To: <3D87E0C2.6040004@mandrakesoft.com> References: <3D87A4A2.6050403@mandrakesoft.com> <20020917.144911.43656989.davem@redhat.com> <3D87E0C2.6040004@mandrakesoft.com> X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Jeff Garzik Date: Tue, 17 Sep 2002 22:11:14 -0400 You're looking at at least one extra get-irq-status too, at least in the classical 10/100 drivers I'm used to seeing... How so? The number of ones done in the e1000 NAPI code are the same (read register until no interesting status bits remain set, same as pre-NAPI e1000 driver). For tg3 it's a cheap memory read from the status block not a PIO.