From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753844AbZHZV0V (ORCPT ); Wed, 26 Aug 2009 17:26:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753303AbZHZV0U (ORCPT ); Wed, 26 Aug 2009 17:26:20 -0400 Received: from electric-eye.fr.zoreil.com ([213.41.134.224]:57607 "EHLO electric-eye.fr.zoreil.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751011AbZHZV0U (ORCPT ); Wed, 26 Aug 2009 17:26:20 -0400 Date: Wed, 26 Aug 2009 23:30:24 +0200 From: Francois Romieu To: "Eric W. Biederman" Cc: David Dillow , Michael Riepe , Michael Buesch , Rui Santos , Michael B??ker , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH] r8169: Reduce looping in the interrupt handler. Message-ID: <20090826213024.GA20428@electric-eye.fr.zoreil.com> References: <1251169150.4023.11.camel@obelisk.thedillows.org> <1251232848.9607.15.camel@lap75545.ornl.gov> <20090825221903.GA13630@electric-eye.fr.zoreil.com> <1251294974.14241.9.camel@obelisk.thedillows.org> <1251295175.14241.11.camel@obelisk.thedillows.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Organisation: Land of Sunshine Inc. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Eric W. Biederman : [...] > It is a bit weird but it also means we aren't playing silly games > with status inside the loop. So if we go through the loop we ack > everything in status. I fear we have some longstanding problem anyway : 1. quiescent state 2. packets are received 3. rtl8169_interrupt schedules napi, clears IntrStatus and exits 4. packets are received and some non-napi event happens 5. rtl8169_interrupt wakes up, reads IntrStatus and goes on... 6. rtl8169_poll wakes up, processes Rx and Tx napi events and goes on... 7. tp->intr_mask still equals ~tp->napi_event : rtl8169_interrupt handler does not even try to schedule napi. 8. more packets are received 9. rtl8169_interrupt clears IntrStatus a. rtl8169_poll reenables napi scheduling, updates IntrMask and exits b. rtl8169_interrupt reads a perfectly clean IntrStatus and exits -- Ueimor