From patchwork Tue Apr 26 01:55:41 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 614758 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3qv5m145VFz9t5w for ; Tue, 26 Apr 2016 11:56:01 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751965AbcDZBzr (ORCPT ); Mon, 25 Apr 2016 21:55:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51407 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750821AbcDZBzq (ORCPT ); Mon, 25 Apr 2016 21:55:46 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4BF2B3B747; Tue, 26 Apr 2016 01:55:45 +0000 (UTC) Received: from hp-dl380pg8-02.lab.eng.pek2.redhat.com (hp-dl380pg8-02.lab.eng.pek2.redhat.com [10.73.8.12]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u3Q1tgGL018098; Mon, 25 Apr 2016 21:55:43 -0400 From: Jason Wang To: davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jason Wang , "Michael S. Tsirkin" Subject: [PATCH net-next] tuntap: calculate rps hash only when needed Date: Mon, 25 Apr 2016 21:55:41 -0400 Message-Id: <1461635741-18857-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org There's no need to calculate rps hash if it was not enabled. So this patch export rps_needed and check it before trying to get rps hash. Tests (using pktgen to inject packets to guest) shows this can improve pps about 13% (when rps is disabled). Before: ~1150000 pps After: ~1300000 pps Cc: Michael S. Tsirkin Signed-off-by: Jason Wang --- drivers/net/tun.c | 2 +- net/core/dev.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index afdf950..746877f 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -819,7 +819,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) if (txq >= numqueues) goto drop; - if (numqueues == 1) { + if (numqueues == 1 && static_key_false(&rps_needed)) { /* Select queue was not called for the skbuff, so we extract the * RPS hash and save it into the flow_table here. */ diff --git a/net/core/dev.c b/net/core/dev.c index b9bcbe7..d4ba936 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3428,6 +3428,7 @@ u32 rps_cpu_mask __read_mostly; EXPORT_SYMBOL(rps_cpu_mask); struct static_key rps_needed __read_mostly; +EXPORT_SYMBOL(rps_needed); static struct rps_dev_flow * set_rps_cpu(struct net_device *dev, struct sk_buff *skb,