From patchwork Fri May 1 13:21:07 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: 226515 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 7853DC47254 for ; Fri, 1 May 2020 13:56:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5301620708 for ; Fri, 1 May 2020 13:56:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588341371; bh=Do1MKtQwU5B4HtI4gZ3Q52PmZmllkDlWjxz/JdLtaB8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=U+0KWUkOxJuGNZvME+/n2uAm+/A51DArVijzH99X434khNaCNsHdctVXNvSm2DoDF ghIORbBEjs8EFp9faoLVr1dTG2CaULqxc84FqgRD02GgoL3D8cbGEfvelmwy5lDfxH /su8PKdBI1WbGYjpRUSefQVzQBHxrNBWypaB9lmw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730452AbgEAN4K (ORCPT ); Fri, 1 May 2020 09:56:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:58036 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729730AbgEANcw (ORCPT ); Fri, 1 May 2020 09:32:52 -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 0549B24957; Fri, 1 May 2020 13:32:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588339972; bh=Do1MKtQwU5B4HtI4gZ3Q52PmZmllkDlWjxz/JdLtaB8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DAuUEU3pJtALyFbN7X8CZ7EFiDmrlUnjYc3fOSa0uLu4Map2DsYHYhw1+WKQmdnCn eDP8JFFyX1DY3uxioB/lo/zsp+ABcNQcgvKru+kZdIJQHGipIb4MBBq5FiKXUViJij LB2qroOW2JlKdnDoDlplYfByfDR8L9ksSrOBbZ7Y= 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 4.14 031/117] tcp: cache line align MAX_TCP_HEADER Date: Fri, 1 May 2020 15:21:07 +0200 Message-Id: <20200501131548.538900548@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131544.291247695@linuxfoundation.org> References: <20200501131544.291247695@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 @@ -55,7 +55,7 @@ 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)