From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [BUG] via-rhine: NOHZ: local_softirq_pending 08 Date: Tue, 29 Jan 2013 22:53:28 -0500 (EST) Message-ID: <20130129.225328.896248042332851696.davem@davemloft.net> References: <51007b84.03ab640a.1cde.fffff62a@mx.google.com> <20130129.174702.196275387733819730.davem@davemloft.net> <20130130000432.GA28621@electric-eye.fr.zoreil.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: jamie.gloudon@gmail.com, netdev@vger.kernel.org, rl@hellgate.ch To: romieu@fr.zoreil.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:35172 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753033Ab3A3Dxc (ORCPT ); Tue, 29 Jan 2013 22:53:32 -0500 In-Reply-To: <20130130000432.GA28621@electric-eye.fr.zoreil.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Francois Romieu Date: Wed, 30 Jan 2013 01:04:32 +0100 > David Miller : > [...] >> I don't think you can't keep using dev_kfree_skb_irq() there. >> >> Francois any objections to this patch? > > None. > > I have almost surely broken via-rhine with NOHZ as I broke the r8169 > driver before 7dbb491878a2c51d372a8890fa45a8ff80358af1. Something like > the patch below could be needed as well (quick shot before bed time > and ~24h delay if Jamie wants to try something now). Good catch, Jamie can you test this combined patch for us? ==================== via-rhine: Fix bugs in NAPI support. 1) rhine_tx() should use dev_kfree_skb() not dev_kfree_skb_irq() 2) rhine_slow_event_task's NAPI triggering logic is racey, it should just hit the interrupt mask register. This is the same as commit 7dbb491878a2c51d372a8890fa45a8ff80358af1 ("r8169: avoid NAPI scheduling delay.") made to fix the same problem in the r8169 driver. From Francois Romieu. Reported-by: Jamie Gloudon Signed-off-by: David S. Miller diff --git a/drivers/net/ethernet/via/via-rhine.c b/drivers/net/ethernet/via/via-rhine.c index 7992b3e..78ace59 100644 --- a/drivers/net/ethernet/via/via-rhine.c +++ b/drivers/net/ethernet/via/via-rhine.c @@ -1801,7 +1801,7 @@ static void rhine_tx(struct net_device *dev) rp->tx_skbuff[entry]->len, PCI_DMA_TODEVICE); } - dev_kfree_skb_irq(rp->tx_skbuff[entry]); + dev_kfree_skb(rp->tx_skbuff[entry]); rp->tx_skbuff[entry] = NULL; entry = (++rp->dirty_tx) % TX_RING_SIZE; } @@ -2010,11 +2010,7 @@ static void rhine_slow_event_task(struct work_struct *work) if (intr_status & IntrPCIErr) netif_warn(rp, hw, dev, "PCI error\n"); - napi_disable(&rp->napi); - rhine_irq_disable(rp); - /* Slow and safe. Consider __napi_schedule as a replacement ? */ - napi_enable(&rp->napi); - napi_schedule(&rp->napi); + iowrite16(RHINE_EVENT & 0xffff, rp->base + IntrEnable); out_unlock: mutex_unlock(&rp->task_lock);