From mboxrd@z Thu Jan 1 00:00:00 1970 From: Changli Gao Subject: [PATCH] net: fix softnet_stat Date: Thu, 15 Apr 2010 11:01:53 +0800 Message-ID: <1271300513-9995-1-git-send-email-xiaosuo@gmail.com> Cc: Tom Herbert , Eric Dumazet , netdev@vger.kernel.org, Changli Gao To: "David S. Miller" Return-path: Received: from mail-pv0-f174.google.com ([74.125.83.174]:56294 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756519Ab0DODBf (ORCPT ); Wed, 14 Apr 2010 23:01:35 -0400 Received: by pva18 with SMTP id 18so544451pva.19 for ; Wed, 14 Apr 2010 20:01:34 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: fix softnet_stat Per cpu variable softnet_data.total was shared between IRQ and SoftIRQ context without any protection. And enqueue_to_backlog should update the netdev_rx_stat of the target CPU. This patch changes the meaning of softnet_data.total to the number of packets processed, not includes dropped, in order to avoid it sharing between IRQ and SoftIRQ. And softnet_data.dropped is protected in the corresponding input_pkt_queue.lock, if RPS is enabled. Signed-off-by: Changli Gao ---- net/core/dev.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index a10a216..b38a991 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2336,7 +2336,6 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu) queue = &per_cpu(softnet_data, cpu); local_irq_save(flags); - __get_cpu_var(netdev_rx_stat).total++; rps_lock(queue); if (queue->input_pkt_queue.qlen <= netdev_max_backlog) { @@ -2366,9 +2365,9 @@ enqueue: goto enqueue; } + per_cpu(netdev_rx_stat, cpu).dropped++; rps_unlock(queue); - __get_cpu_var(netdev_rx_stat).dropped++; local_irq_restore(flags); kfree_skb(skb); @@ -3565,7 +3564,7 @@ static int softnet_seq_show(struct seq_file *seq, void *v) struct netif_rx_stats *s = v; seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n", - s->total, s->dropped, s->time_squeeze, 0, + s->total + s->dropped, s->dropped, s->time_squeeze, 0, 0, 0, 0, 0, /* was fastroute */ s->cpu_collision, s->received_rps); return 0;