From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin KaFai Lau Subject: [PATCH RFC v2 net-next 0/2] ip_tunnel: Create percpu gro_cell Date: Tue, 13 Jan 2015 15:42:42 -0800 Message-ID: <1421192564-437455-1-git-send-email-kafai@fb.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Eric Dumazet , To: Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:58279 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753891AbbAMXn3 (ORCPT ); Tue, 13 Jan 2015 18:43:29 -0500 Received: from pps.filterd (m0004003 [127.0.0.1]) by mx0b-00082601.pphosted.com (8.14.5/8.14.5) with SMTP id t0DNdEIw023623 for ; Tue, 13 Jan 2015 15:43:29 -0800 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0b-00082601.pphosted.com with ESMTP id 1rw9qm0rvg-3 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=OK) for ; Tue, 13 Jan 2015 15:43:29 -0800 Received: from facebook.com (2401:db00:20:7029:face:0:33:0) by mx-out.facebook.com (10.212.232.59) with ESMTP id f7d2221e9b7d11e485eb0002c991e86a-143df390 for ; Tue, 13 Jan 2015 15:43:26 -0800 Sender: netdev-owner@vger.kernel.org List-ID: In the ipip tunnel, the skb->queue_mapping is lost in ipip_rcv(). All skb will be queued to the same cell->napi_skbs. The gro_cell_poll is pinned to one core under load. In production traffic, we also see severe rx_dropped in the tunl iface and it is probably due to this limit: skb_queue_len(&cell->napi_skbs) > netdev_max_backlog This patch is trying to alloc_percpu(struct gro_cell) and schedule gro_cell_poll to process the skb in the same core. Changes from v1: Eric Dumazet pointed out that ____cacheline_aligned_in_smp is no longer needed. Setup: VIP_PREFIX=9.9.9.9/32 REMOTE_REAL_IP=10.228.95.75 if [ "$1" = "encap" ] then sudo ip tunnel add mode ipip remote ${REMOTE_REAL_IP} sudo ip link set dev ipip0 up sudo ip route add dev ipip0 ${VIP_PREFIX} else # Decapsulating host sudo ip tunnel add mode ipip sudo ip link set dev tunl0 up sudo ip addr add dev lo ${VIP_PREFIX} sudo sysctl -a | grep '\.rp_filter' | awk '{print $1;}' | \ xargs -n1 -I{} sudo sysctl {}=0 fi Before: [root@DECAP ~]# netserver -p 8888 [root@ENCAP ~]# super_netperf 200 -t TCP_RR -H 9.9.9.9 -p 8888 \ -l 30 -- -d 0x6 -m 8k,64k -s 1M -S 1M 332215 [root@DECAP ~]# perf probe -a gro_cell_poll [root@DECAP ~]# perf stat -I 1000 -a -A -e probe:gro_cell_poll 117.258518273 CPU0 0 probe:gro_cell_poll 117.258518273 CPU1 0 probe:gro_cell_poll 117.258518273 CPU2 0 probe:gro_cell_poll 117.258518273 CPU3 0 probe:gro_cell_poll 117.258518273 CPU4 0 probe:gro_cell_poll 117.258518273 CPU5 0 probe:gro_cell_poll 117.258518273 CPU6 0 probe:gro_cell_poll 117.258518273 CPU7 0 probe:gro_cell_poll 117.258518273 CPU8 0 probe:gro_cell_poll 117.258518273 CPU9 0 probe:gro_cell_poll 117.258518273 CPU10 0 probe:gro_cell_poll 117.258518273 CPU11 0 probe:gro_cell_poll 117.258518273 CPU12 0 probe:gro_cell_poll 117.258518273 CPU13 0 probe:gro_cell_poll 117.258518273 CPU14 0 probe:gro_cell_poll 117.258518273 CPU15 4,882 probe:gro_cell_poll 117.258518273 CPU16 0 probe:gro_cell_poll 117.258518273 CPU17 0 probe:gro_cell_poll 117.258518273 CPU18 0 probe:gro_cell_poll 117.258518273 CPU19 0 probe:gro_cell_poll 117.258518273 CPU20 0 probe:gro_cell_poll 117.258518273 CPU21 0 probe:gro_cell_poll 117.258518273 CPU22 0 probe:gro_cell_poll 117.258518273 CPU23 0 probe:gro_cell_poll 117.258518273 CPU24 0 probe:gro_cell_poll 117.258518273 CPU25 0 probe:gro_cell_poll 117.258518273 CPU26 0 probe:gro_cell_poll 117.258518273 CPU27 0 probe:gro_cell_poll 117.258518273 CPU28 0 probe:gro_cell_poll 117.258518273 CPU29 0 probe:gro_cell_poll 117.258518273 CPU30 0 probe:gro_cell_poll 117.258518273 CPU31 0 probe:gro_cell_poll 117.258518273 CPU32 0 probe:gro_cell_poll 117.258518273 CPU33 0 probe:gro_cell_poll 117.258518273 CPU34 0 probe:gro_cell_poll 117.258518273 CPU35 0 probe:gro_cell_poll 117.258518273 CPU36 0 probe:gro_cell_poll 117.258518273 CPU37 0 probe:gro_cell_poll 117.258518273 CPU38 0 probe:gro_cell_poll 117.258518273 CPU39 0 probe:gro_cell_poll After: [root@DECAP ~]# netserver -p 8888 [root@ENCAP ~]# super_netperf 200 -t TCP_RR -H 9.9.9.9 -p 8888 \ -l 30 -- -d 0x6 -m 8k,64k -s 1M -S 1M 877530 [root@DECAP ~]# perf probe -a gro_cell_poll [root@DECAP ~]# perf stat -I 1000 -a -A -e probe:gro_cell_poll 40.085714389 CPU0 13,607 probe:gro_cell_poll 40.085714389 CPU1 13,188 probe:gro_cell_poll 40.085714389 CPU2 12,913 probe:gro_cell_poll 40.085714389 CPU3 12,790 probe:gro_cell_poll 40.085714389 CPU4 13,395 probe:gro_cell_poll 40.085714389 CPU5 13,121 probe:gro_cell_poll 40.085714389 CPU6 11,083 probe:gro_cell_poll 40.085714389 CPU7 12,945 probe:gro_cell_poll 40.085714389 CPU8 13,704 probe:gro_cell_poll 40.085714389 CPU9 13,514 probe:gro_cell_poll 40.085714389 CPU10 0 probe:gro_cell_poll 40.085714389 CPU11 0 probe:gro_cell_poll 40.085714389 CPU12 0 probe:gro_cell_poll 40.085714389 CPU13 0 probe:gro_cell_poll 40.085714389 CPU14 0 probe:gro_cell_poll 40.085714389 CPU15 0 probe:gro_cell_poll 40.085714389 CPU16 0 probe:gro_cell_poll 40.085714389 CPU17 0 probe:gro_cell_poll 40.085714389 CPU18 0 probe:gro_cell_poll 40.085714389 CPU19 0 probe:gro_cell_poll 40.085714389 CPU20 10,402 probe:gro_cell_poll 40.085714389 CPU21 12,312 probe:gro_cell_poll 40.085714389 CPU22 11,913 probe:gro_cell_poll 40.085714389 CPU23 12,964 probe:gro_cell_poll 40.085714389 CPU24 13,727 probe:gro_cell_poll 40.085714389 CPU25 12,943 probe:gro_cell_poll 40.085714389 CPU26 13,558 probe:gro_cell_poll 40.085714389 CPU27 12,676 probe:gro_cell_poll 40.085714389 CPU28 13,754 probe:gro_cell_poll 40.085714389 CPU29 13,379 probe:gro_cell_poll 40.085714389 CPU30 0 probe:gro_cell_poll 40.085714389 CPU31 0 probe:gro_cell_poll 40.085714389 CPU32 0 probe:gro_cell_poll 40.085714389 CPU33 0 probe:gro_cell_poll 40.085714389 CPU34 0 probe:gro_cell_poll 40.085714389 CPU35 0 probe:gro_cell_poll 40.085714389 CPU36 0 probe:gro_cell_poll 40.085714389 CPU37 0 probe:gro_cell_poll 40.085714389 CPU38 0 probe:gro_cell_poll 40.085714389 CPU39 0 probe:gro_cell_poll