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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 7C995C282C5 for ; Thu, 24 Jan 2019 20:09:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4054C218A6 for ; Thu, 24 Jan 2019 20:09:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548360561; bh=PS2fBftkJI0/VZcvshlPgLZoKY8UgCeWZnDyWvKEx30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VICOTifbgdq3UzqB18YoiYLEmgI4bWcb3MIOVe8Ogsf0ZNNXRqeZAtewQdT3VFoB6 QtTf7GEzwtyKr40/4WLe9VjpKFVxfLFhYPRl8TO8Qys+iJIJETZMjn5FWOblcuZT2p LwsKiDhnwAzxvwJD/y8yd0Q4waa3IGA1IoXlizgI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730551AbfAXT2f (ORCPT ); Thu, 24 Jan 2019 14:28:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:55360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730379AbfAXT2f (ORCPT ); Thu, 24 Jan 2019 14:28:35 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 727B3218A6; Thu, 24 Jan 2019 19:28:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548358114; bh=PS2fBftkJI0/VZcvshlPgLZoKY8UgCeWZnDyWvKEx30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UuLqSDOV8BxruUWr5ZnYQtj1lrnV73E1fQtGvCB/AnQkDPp7vwue84u72j7Xcfu5L 8yG1cgWF2cPqKl7A7uAidAdSWh+bEs5xmNecUVNogk2N1W88J12bxTVekrIw+82WlO 51ibPKXh+s+YD5iGhKhIOPzPQnf31jncACbQOAvU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "David S. Miller" , Mao Wenan Subject: [PATCH 4.4 103/104] net: speed up skb_rbtree_purge() Date: Thu, 24 Jan 2019 20:20:32 +0100 Message-Id: <20190124190205.798431289@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124190154.968308875@linuxfoundation.org> References: <20190124190154.968308875@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 7c90584c66cc4b033a3b684b0e0950f79e7b7166 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- net/core/skbuff.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- 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); + } } /**