Subject: [PATCH net-next 0/2] net/sched: remove spinlock from 'csum' action

From: Davide Caratti <[email-masked]>
Date: Wed, 13 Dec 2017 10:48:36 +0100

Similarly to what has been done earlier with other actions [1][2], this
series tries to improve the performance of 'csum' tc action, removing a
spinlock in the data plane. Patch 1 lets act_csum use per-CPU counters;
patch 2 removes spin_{,un}lock_bh() calls from act() method.

test procedure:

 # ip link add name eth1 type dummy
 # ip link set dev eth1 up
 # tc qdisc add dev eth1 root handle 1: prio
 # tc filter add dev eth1 parent 1: matchall action csum udp
 # for n in 2 4 6 8 10 12 14 16; do
 > ./pktgen_bench_xmit_mode_queue_xmit.sh -v -s 64 -t $n -n 1000000 -i eth1
 > done

test results:

 $n |  avg. pps/core  | avg. pps/core | delta
    | (without patch) | (with patch)  |  (%)
 ---+-----------------+---------------+------
  2 |          484915 |        547716 |   13
  4 |          209551 |        254439 |   21
  6 |          143901 |        164695 |   14
  8 |          112423 |        127821 |   14
 10 |           91134 |        102950 |   13
 12 |           75374 |         85499 |   13
 14 |           64586 |         73426 |   14
 16 |           56635 |         64111 |   13

references:

[1] http://www.spinics.net/lists/netdev/msg334760.html
[2] https://www.spinics.net/lists/netdev/msg465862.html

Davide Caratti (2):
  net/sched: act_csum: use per-core statistics
  net/sched: act_csum: don't use spinlock in the fast path

 net/sched/act_csum.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

-- 
2.13.6