From patchwork Fri May 1 13:21:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226683 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=ham 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 030F1C47254 for ; Fri, 1 May 2020 13:29:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE3132173E for ; Fri, 1 May 2020 13:28:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339739; bh=kVEuf2gaxCNZnPQLaEEHOFcGlNG9hxk+Tp1dBik2BeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=d8V6FrDCxNVLLNnbCHSTJA1TM/Cs3oruWnNoead6uIfF6gMMCasgIh9yUHESssC6U IyJDMqA2K0EmTlXmjV557A17wM4SrBhurkfRkPTKmKE+qiP7ExI/TwgJl45u8bGDS6 s2CGk8YtmVT+z7TCegBaUMI++rebERu11fB5AvfA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729717AbgEAN26 (ORCPT ); Fri, 1 May 2020 09:28:58 -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 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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)