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,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 17016C83004 for ; Tue, 28 Apr 2020 18:54:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB7EE206D6 for ; Tue, 28 Apr 2020 18:54:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588100058; bh=noDKrL1XZ7S66q2XxiX3wRm8Ysr3RMy4fpVkvvvA9UE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iytk1gOx20ItvwMour9rxc9KTBIQn0AxL00ZOhuqvwk4lYU/SSbla4r6eNrDDkKcJ gDcix1kQoV0UxvmgFgnCjVXrH/0+J322djbywAM5uPbKDqhihLT7grYG5p5zRJ26Iy MgmT16QrRTo5S6bvP+ZsxGfCJkXf4oJDqpHwm1XE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730757AbgD1SyS (ORCPT ); Tue, 28 Apr 2020 14:54:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:50640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729263AbgD1Sd7 (ORCPT ); Tue, 28 Apr 2020 14:33:59 -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 EFA5020B80; Tue, 28 Apr 2020 18:33:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098839; bh=noDKrL1XZ7S66q2XxiX3wRm8Ysr3RMy4fpVkvvvA9UE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Oyo8WMYKvNqilE2qNhfsDe6xJLgIqlLnR15TV2HlG2AIuDixQyVBXdlc1sZPxz85z TSdXv5n6mt2SoZ0OMqFgxs47PgZpex3QSAjYdpC7ttSY6r0teG8KA6vtOmrHRr5dC9 sdpoFO1uFZ3zfSRI89MiMLXybiW/HPzl4GDIw90I= 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 4.19 063/131] tcp: cache line align MAX_TCP_HEADER Date: Tue, 28 Apr 2020 20:24:35 +0200 Message-Id: <20200428182232.875882123@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182224.822179290@linuxfoundation.org> References: <20200428182224.822179290@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 @@ -53,7 +53,7 @@ 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)