From: Martin KaFai Lau <kafai@fb.com>
To: <netdev@vger.kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>, <kernel-team@fb.com>
Subject: [PATCH RFC v2 net-next 0/2] ip_tunnel: Create percpu gro_cell
Date: Tue, 13 Jan 2015 15:42:42 -0800 [thread overview]
Message-ID: <1421192564-437455-1-git-send-email-kafai@fb.com> (raw)
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
next reply other threads:[~2015-01-13 23:43 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-13 23:42 Martin KaFai Lau [this message]
2015-01-13 23:42 ` [PATCH RFC v2 net-next 1/2] ip_tunnel: Create percpu gro_cell Martin KaFai Lau
2015-01-15 0:14 ` Eric Dumazet
2015-01-13 23:42 ` [PATCH RFC v2 net-next 2/2] ip_tunnel: Remove struct gro_cells Martin KaFai Lau
2015-01-14 22:53 ` Eric Dumazet
2015-01-15 18:39 ` Martin Lau
2015-01-15 19:24 ` Eric Dumazet
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