From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934996Ab3BTTa1 (ORCPT ); Wed, 20 Feb 2013 14:30:27 -0500 Received: from mail-da0-f52.google.com ([209.85.210.52]:47096 "EHLO mail-da0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934380Ab3BTTaV (ORCPT ); Wed, 20 Feb 2013 14:30:21 -0500 Message-ID: <1361388619.19353.221.camel@edumazet-glaptop> Subject: Re: Kernel 3.7.2 strange warning and short system hang From: Eric Dumazet To: David Miller Cc: bind@enas.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Date: Wed, 20 Feb 2013 11:30:19 -0800 In-Reply-To: <20130220.125715.2150428275032134361.davem@davemloft.net> References: <5124F57A.6080908@enas.net> <1361379176.19353.187.camel@edumazet-glaptop> <20130220.125715.2150428275032134361.davem@davemloft.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2013-02-20 at 12:57 -0500, David Miller wrote: > I've seen this pattern on several occasions and I have to wonder... > > Do we really require, therefore, every NAPI driver to use dev_kfree_skb_any() > in it's TX reclaim if it supports netpoll? > > That seems completely bogus. > > netpoll is supposed to provide an execution environment when it invokes > ->poll() that is identical to the normal NAPI execution. If that would > be true, then this change above would be completely unnecessary. > > We need to figure out what is the case here, and audit all the NAPI > drivers to make sure they do the right thing once we know what the > right thing actually is. netpoll directly calls n->poll() (poll_napi() -> poll_one_napi() -> napi->poll(napi, budget) ) Presumably it should not do that if running in interrupt context.