From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38B51C282C6 for ; Fri, 25 Jan 2019 02:43:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19030218D2 for ; Fri, 25 Jan 2019 02:43:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728558AbfAYCnX (ORCPT ); Thu, 24 Jan 2019 21:43:23 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:47384 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726107AbfAYCnX (ORCPT ); Thu, 24 Jan 2019 21:43:23 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id BC9D49DCF25A4E724555; Fri, 25 Jan 2019 10:43:21 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.408.0; Fri, 25 Jan 2019 10:43:13 +0800 From: Mao Wenan To: , , , , , , Subject: [PATCH stable 4.4 v2 01/11] net: speed up skb_rbtree_purge() Date: Fri, 25 Jan 2019 10:48:34 +0800 Message-ID: <1548384524-174152-2-git-send-email-maowenan@huawei.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1548384524-174152-1-git-send-email-maowenan@huawei.com> References: <1548384524-174152-1-git-send-email-maowenan@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet [ Upstream commit 7c90584c66cc4b033a3b684b0e0950f79e7b7166 ] As measured in my prior patch ("sch_netem: faster rb tree removal"), rbtree_postorder_for_each_entry_safe() is nice looking but much slower than using rb_next() directly, except when tree is small enough to fit in CPU caches (then the cost is the same) Also note that there is not even an increase of text size : $ size net/core/skbuff.o.before net/core/skbuff.o text data bss dec hex filename 40711 1298 0 42009 a419 net/core/skbuff.o.before 40711 1298 0 42009 a419 net/core/skbuff.o From: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Mao Wenan --- net/core/skbuff.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9703924..8a57bba 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2388,12 +2388,15 @@ EXPORT_SYMBOL(skb_queue_purge); */ void skb_rbtree_purge(struct rb_root *root) { - struct sk_buff *skb, *next; + struct rb_node *p = rb_first(root); - rbtree_postorder_for_each_entry_safe(skb, next, root, rbnode) - kfree_skb(skb); + while (p) { + struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode); - *root = RB_ROOT; + p = rb_next(p); + rb_erase(&skb->rbnode, root); + kfree_skb(skb); + } } /** -- 1.8.3.1