From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Taht Subject: [PATCH net-next] sch_cake: Make gso-splitting configurable from userspace Date: Thu, 26 Jul 2018 19:45:10 -0700 Message-ID: <1532659510-17385-2-git-send-email-dave.taht@gmail.com> References: <1532659510-17385-1-git-send-email-dave.taht@gmail.com> Cc: Dave Taht To: netdev@vger.kernel.org, cake@lists.bufferbloat.net Return-path: Received: from mail-pg1-f194.google.com ([209.85.215.194]:40276 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725803AbeG0EFC (ORCPT ); Fri, 27 Jul 2018 00:05:02 -0400 Received: by mail-pg1-f194.google.com with SMTP id x5-v6so2320970pgp.7 for ; Thu, 26 Jul 2018 19:45:24 -0700 (PDT) In-Reply-To: <1532659510-17385-1-git-send-email-dave.taht@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: This patch restores cake's deployed behavior at line rate to always split gso, and makes gso splitting configurable from userspace. running cake unlimited (unshaped) at 1gigE, local traffic: no-split-gso bql limit: 131966 split-gso bql limit: ~42392-45420 On this 4 stream test splitting gso apart results in halving the observed interpacket latency at no loss in throughput. Summary of tcp_nup test run 'gso-split' (at 2018-07-26 16:03:51.824728): Ping (ms) ICMP : 0.83 0.81 ms 341 TCP upload avg : 235.43 235.39 Mbits/s 301 TCP upload sum : 941.71 941.56 Mbits/s 301 TCP upload::1 : 235.45 235.43 Mbits/s 271 TCP upload::2 : 235.45 235.41 Mbits/s 289 TCP upload::3 : 235.40 235.40 Mbits/s 288 TCP upload::4 : 235.41 235.40 Mbits/s 291 verses Summary of tcp_nup test run 'no-split-gso' (at 2018-07-26 16:37:23.563960): avg median # data pts Ping (ms) ICMP : 1.67 1.73 ms 348 TCP upload avg : 234.56 235.37 Mbits/s 301 TCP upload sum : 938.24 941.49 Mbits/s 301 TCP upload::1 : 234.55 235.38 Mbits/s 285 TCP upload::2 : 234.57 235.37 Mbits/s 286 TCP upload::3 : 234.58 235.37 Mbits/s 274 TCP upload::4 : 234.54 235.42 Mbits/s 288 --- net/sched/sch_cake.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 539c949..35fc725 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -80,7 +80,6 @@ #define CAKE_QUEUES (1024) #define CAKE_FLOW_MASK 63 #define CAKE_FLOW_NAT_FLAG 64 -#define CAKE_SPLIT_GSO_THRESHOLD (125000000) /* 1Gbps */ /* struct cobalt_params - contains codel and blue parameters * @interval: codel initial drop rate @@ -2569,10 +2568,12 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt, if (tb[TCA_CAKE_MEMORY]) q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]); - if (q->rate_bps && q->rate_bps <= CAKE_SPLIT_GSO_THRESHOLD) - q->rate_flags |= CAKE_FLAG_SPLIT_GSO; - else - q->rate_flags &= ~CAKE_FLAG_SPLIT_GSO; + if (tb[TCA_CAKE_SPLIT_GSO]) { + if (!!nla_get_u32(tb[TCA_CAKE_SPLIT_GSO])) + q->rate_flags |= CAKE_FLAG_SPLIT_GSO; + else + q->rate_flags &= ~CAKE_FLAG_SPLIT_GSO; + } if (q->tins) { sch_tree_lock(sch); @@ -2608,7 +2609,7 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt, q->target = 5000; /* 5ms: codel RFC argues * for 5 to 10% of interval */ - + q->rate_flags |= CAKE_FLAG_SPLIT_GSO; q->cur_tin = 0; q->cur_flow = 0; -- 2.7.4