From patchwork Thu May 10 08:28:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gao Feng X-Patchwork-Id: 911311 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=vip.163.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40hRP22mkbz9s2t for ; Thu, 10 May 2018 18:35:01 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756754AbeEJIe5 (ORCPT ); Thu, 10 May 2018 04:34:57 -0400 Received: from mail-177180.vip.163.com ([123.58.177.180]:44956 "EHLO mail-177180.vip.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756650AbeEJIez (ORCPT ); Thu, 10 May 2018 04:34:55 -0400 X-Greylist: delayed 309 seconds by postgrey-1.27 at vger.kernel.org; Thu, 10 May 2018 04:34:54 EDT Received: from ikuai8.com (unknown [124.64.164.112]) by smtp1 (Coremail) with SMTP id oGZ4CgDnZsaVAvRa_zMYDg--.18856S2; Thu, 10 May 2018 16:28:15 +0800 (CST) From: gfree.wind@vip.163.com To: davem@davemloft.net, daniel@iogearbox.net, jakub.kicinski@netronome.com, dsahern@gmail.com, netdev@vger.kernel.org Cc: Gao Feng Subject: [PATCH net] net: Correct wrong skb_flow_limit check when enable RPS Date: Thu, 10 May 2018 16:28:04 +0800 Message-Id: <1525940884-21067-1-git-send-email-gfree.wind@vip.163.com> X-Mailer: git-send-email 1.9.1 X-CM-TRANSID: oGZ4CgDnZsaVAvRa_zMYDg--.18856S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7WFWUtF4rZF4fGr13KrW8Xrb_yoW8Aw1rpF WUGr1UKF1vvFsrurZFqrs7Zw1Yyw1rKr13GFZ5Kas3Cr15tr1vgFyxK34Yvr1fCFZ5ZrW5 Jr12vaykua1kZ3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jjQ6LUUUUU= X-Originating-IP: [124.64.164.112] X-CM-SenderInfo: 5jiuvvgozl0vg6yl1hqrwthudrp/1tbiDB9Cs1gEhZvRDgAAs- Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Gao Feng The skb flow limit is implemented for each CPU independently. In the current codes, the function skb_flow_limit gets the softnet_data by this_cpu_ptr. But the target cpu of enqueue_to_backlog would be not the current cpu when enable RPS. As the result, the skb_flow_limit checks the stats of current CPU, while the skb is going to append the queue of another CPU. It isn't the expected behavior. Now pass the softnet_data as a param to softnet_data to make consistent. Signed-off-by: Gao Feng --- net/core/dev.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index af0558b..0f98eff 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3883,18 +3883,15 @@ static int rps_ipi_queued(struct softnet_data *sd) int netdev_flow_limit_table_len __read_mostly = (1 << 12); #endif -static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) +static bool skb_flow_limit(struct softnet_data *sd, struct sk_buff *skb, unsigned int qlen) { #ifdef CONFIG_NET_FLOW_LIMIT struct sd_flow_limit *fl; - struct softnet_data *sd; unsigned int old_flow, new_flow; if (qlen < (netdev_max_backlog >> 1)) return false; - sd = this_cpu_ptr(&softnet_data); - rcu_read_lock(); fl = rcu_dereference(sd->flow_limit); if (fl) { @@ -3938,7 +3935,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu, if (!netif_running(skb->dev)) goto drop; qlen = skb_queue_len(&sd->input_pkt_queue); - if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) { + if (qlen <= netdev_max_backlog && !skb_flow_limit(sd, skb, qlen)) { if (qlen) { enqueue: __skb_queue_tail(&sd->input_pkt_queue, skb);