From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 6/7] : tehuti Fix possible causing oops of net_rx_action Date: Tue, 11 Dec 2007 21:53:50 -0800 Message-ID: <20071211215350.1bf86d02@freepuppy.rosehill> References: <002901c83c73$b089b6e0$9c94fea9@jason> <20071211213939.122de1db@freepuppy.rosehill> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jgarzik@pobox.com, baum@tehutinetworks.net, andy@greyhouse.net To: "Joonwoo Park" Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:40313 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752233AbXLLFzz (ORCPT ); Wed, 12 Dec 2007 00:55:55 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 12 Dec 2007 14:48:27 +0900 "Joonwoo Park" wrote: > 2007/12/12, Stephen Hemminger : > > On Wed, 12 Dec 2007 13:01:27 +0900 > > "Joonwoo Park" wrote: > > > > > [NETDEV]: tehuti Fix possible causing oops of net_rx_action > > > > > > Signed-off-by: Joonwoo Park > > > --- > > > drivers/net/tehuti.c | 2 ++ > > > 1 files changed, 2 insertions(+), 0 deletions(-) > > > > > > diff --git a/drivers/net/tehuti.c b/drivers/net/tehuti.c > > > index 21230c9..955e749 100644 > > > --- a/drivers/net/tehuti.c > > > +++ b/drivers/net/tehuti.c > > > @@ -305,6 +305,8 @@ static int bdx_poll(struct napi_struct *napi, int budget) > > > > > > netif_rx_complete(dev, napi); > > > bdx_enable_interrupts(priv); > > > + if (unlikely(work_done == napi->weight)) > > > + return work_done - 1; > > > } > > > return work_done; > > > } > > > > A better fix would be not going over budget in the first place. > > > > -- > > Stephen Hemminger > > > > Stephen, > This is code of bd_poll(). > Do you mean remove napi_stop stuff? > > static int bdx_poll(struct napi_struct *napi, int budget) > { > ... > work_done = bdx_rx_receive(priv, &priv->rxd_fifo0, budget); > if ((work_done < budget) || > (priv->napi_stop++ >= 30)) { Yes remove the napi_stop stuff, because current NAPI expects device to be constrained only by budget. If you need to stop sooner, just set napi weight to be smaller. > DBG("rx poll is done. backing to isr-driven\n"); > > /* from time to time we exit to let NAPI layer release > * device lock and allow waiting tasks (eg rmmod) to advance) */ > priv->napi_stop = 0; > > netif_rx_complete(dev, napi); > bdx_enable_interrupts(priv); With my posted fix to rx_action the following two lines would not be needed. > if (unlikely(work_done == napi->weight)) > return work_done - 1; > } > return work_done; > } > > Thanks, > Joonwoo -- Stephen Hemminger