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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 06CCDC47254 for ; Fri, 1 May 2020 13:29:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0BEB2173E for ; Fri, 1 May 2020 13:29:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339741; bh=kVEuf2gaxCNZnPQLaEEHOFcGlNG9hxk+Tp1dBik2BeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MgKFyXT3HMWtwDNV5oKx0D5/bHzsCapETABWArcDmCWmSAXpIdvWT86BDOi1cpM99 o/9elxND7rMYg4XjsYFRRWv7P0iYnxDpNeLZ7b17gn9VnpuF5ua8kIPa2OwXGLbOwI eA/+QSu7f2QZPKfhqSQW3Yw9E6Dzz4pJ56w1HYhg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729727AbgEAN3A (ORCPT ); Fri, 1 May 2020 09:29:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:52304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729158AbgEAN25 (ORCPT ); Fri, 1 May 2020 09:28:57 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 DADEC2173E; Fri, 1 May 2020 13:28:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339736; bh=kVEuf2gaxCNZnPQLaEEHOFcGlNG9hxk+Tp1dBik2BeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e+gfi278H7xodGJ6E1rTljW5Ek5TkNAE63TAZX2aeUxeGw0y7lg9UxNcjKPF4SvkM bK6N4SHB5CnAYfz1obPwya8JAQst7xlrdYmKs9zKavxrkLJ+Hb7O+oa9Oa9m62FHJB h+Yq16ZnnD1L1m/eB13cBhaSBXekx2POAv5EMWY8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Soheil Hassas Yeganeh , "David S. Miller" Subject: [PATCH 4.9 25/80] tcp: cache line align MAX_TCP_HEADER Date: Fri, 1 May 2020 15:21:19 +0200 Message-Id: <20200501131522.465024046@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131513.810761598@linuxfoundation.org> References: <20200501131513.810761598@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit 9bacd256f1354883d3c1402655153367982bba49 ] TCP stack is dumb in how it cooks its output packets. Depending on MAX_HEADER value, we might chose a bad ending point for the headers. If we align the end of TCP headers to cache line boundary, we make sure to always use the smallest number of cache lines, which always help. Signed-off-by: Eric Dumazet Cc: Soheil Hassas Yeganeh Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/tcp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -51,7 +51,7 @@ extern struct inet_hashinfo tcp_hashinfo extern struct percpu_counter tcp_orphan_count; void tcp_time_wait(struct sock *sk, int state, int timeo); -#define MAX_TCP_HEADER (128 + MAX_HEADER) +#define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) #define MAX_TCP_OPTION_SPACE 40 #define TCP_MIN_SND_MSS 48 #define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE)