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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 1953DC4CECE for ; Fri, 13 Mar 2020 17:07:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED9952076C for ; Fri, 13 Mar 2020 17:07:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726875AbgCMRHf (ORCPT ); Fri, 13 Mar 2020 13:07:35 -0400 Received: from mail.wangsu.com ([123.103.51.227]:40012 "EHLO wangsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726442AbgCMRHf (ORCPT ); Fri, 13 Mar 2020 13:07:35 -0400 X-Greylist: delayed 1154 seconds by postgrey-1.27 at vger.kernel.org; Fri, 13 Mar 2020 13:07:30 EDT Received: from 137.localdomain (unknown [218.107.205.216]) by app2 (Coremail) with SMTP id 4zNnewDnSNZEuWtesuYaAA--.224S3; Sat, 14 Mar 2020 00:48:10 +0800 (CST) From: Pengcheng Yang To: edumazet@google.com, davem@davemloft.net, ncardwell@google.com Cc: netdev@vger.kernel.org, Pengcheng Yang Subject: [PATCH net-next 2/5] tcp: fix stretch ACK bugs in Scalable Date: Sat, 14 Mar 2020 00:47:21 +0800 Message-Id: <1584118044-9798-2-git-send-email-yangpc@wangsu.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1584118044-9798-1-git-send-email-yangpc@wangsu.com> References: <1584118044-9798-1-git-send-email-yangpc@wangsu.com> X-CM-TRANSID: 4zNnewDnSNZEuWtesuYaAA--.224S3 X-Coremail-Antispam: 1UD129KBjvJXoW7Aw4rWryDXr1xJr4furyDJrb_yoW8XFWUpF s8Gw1Fkr45WrySgayS9Fy5JF15GwsavFy7Gry2krn3Aws8Gr93tF1kt3y5tFWUA3yxC39I krWj93WxWF9YyrUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUgI1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l8cAvFVAK 0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4 x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJr0_GcWl84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2 z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4 xG64xvF2IEw4CE5I8CrVC2j2WlYx0E74AGY7Cv6cx26r48McvjeVCFs4IE7xkEbVWUJVW8 JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc2xSY4AK67AK6r1l42 xK82IYc2Ij64vIr41l42xK82IY6x8ErcxFaVAv8VW8GwCFx2IqxVCFs4IE7xkEbVWUJVW8 JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1V AFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xII jxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1I6r4UMIIF0xvEx4 A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU 0xZFpf9x0JjeNtxUUUUU= X-CM-SenderInfo: p1dqw1nf6zt0xjvxhudrp/ Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Change Scalable to properly handle stretch ACKs in additive increase mode by passing in the count of ACKed packets to tcp_cong_avoid_ai(). In addition, because we are now precisely accounting for stretch ACKs, including delayed ACKs, we can now change TCP_SCALABLE_AI_CNT to 100. Signed-off-by: Pengcheng Yang --- net/ipv4/tcp_scalable.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c index 471571e..6cebf41 100644 --- a/net/ipv4/tcp_scalable.c +++ b/net/ipv4/tcp_scalable.c @@ -10,10 +10,9 @@ #include /* These factors derived from the recommended values in the aer: - * .01 and and 7/8. We use 50 instead of 100 to account for - * delayed ack. + * .01 and and 7/8. */ -#define TCP_SCALABLE_AI_CNT 50U +#define TCP_SCALABLE_AI_CNT 100U #define TCP_SCALABLE_MD_SCALE 3 static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 acked) @@ -23,11 +22,13 @@ static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 acked) if (!tcp_is_cwnd_limited(sk)) return; - if (tcp_in_slow_start(tp)) - tcp_slow_start(tp, acked); - else - tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT), - 1); + if (tcp_in_slow_start(tp)) { + acked = tcp_slow_start(tp, acked); + if (!acked) + return; + } + tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT), + acked); } static u32 tcp_scalable_ssthresh(struct sock *sk) -- 1.8.3.1