From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752323Ab3JAWqV (ORCPT ); Tue, 1 Oct 2013 18:46:21 -0400 Received: from violet.fr.zoreil.com ([92.243.8.30]:52500 "EHLO violet.fr.zoreil.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752245Ab3JAWqR (ORCPT ); Tue, 1 Oct 2013 18:46:17 -0400 Date: Wed, 2 Oct 2013 00:45:15 +0200 From: Francois Romieu To: Julia Lawall Cc: "Ruslan N. Marchenko" , linux-kernel@vger.kernel.org Subject: Re: [BUG] Regression in 2fdac010 drivers/net/ethernet/via/via-velocity.c: update napi implementation Message-ID: <20131001224515.GA3113@electric-eye.fr.zoreil.com> References: <20130930071531.GA13037@ruff.mobi> 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/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Julia Lawall : [...] > There has already been a discussion about this, and a patch has already > been proposed. It has to do with lock managament. I will look for the > email. The underlying problem has to do with disabled irq. netif_receive_skb assumes irq to be enabled. Current via-velocity poll() method should narrow its (spinlocked) irq disabled section. What I've done should not require much analysis (aka "what could race with the rx bh processing in a napi driver ?") and avoids a more intrusive lockless napi design. -- Ueimor