Subject: [sctp] ef2820a735: -50% netperf Throughput_Mbps

From: Fengguang Wu <[email-masked]>
Date: Wed, 19 Feb 2014 21:20:34 +0800

Hi Matija,

We noticed the below changes on commit ef2820a735f74ea60335f8ba3801b844f0cb184d
(" net: sctp: Fix a_rwnd/rwnd management to reflect real state of the receiver's buffer")
in netperf SCTP_STREAM tests:

cd0f0b95fd2cd2b  ef2820a735f74ea60335f8ba3  
---------------  -------------------------  
         8 ~ 0%     -50.0%          4 ~ 0%  TOTAL netperf.Throughput_Mbps
     54287 ~44%    +338.1%     237842 ~48%  TOTAL cpuidle.C1E-NHM.time
  12008353 ~12%     -56.0%    5281848 ~ 0%  TOTAL proc-vmstat.pgalloc_normal
    114861 ~ 0%     -50.3%      57085 ~ 3%  TOTAL softirqs.NET_RX
  12964639 ~11%     -55.1%    5818663 ~ 0%  TOTAL proc-vmstat.pgfree
    866489 ~ 0%     -43.3%     491417 ~ 0%  TOTAL proc-vmstat.pgalloc_dma32
    119373 ~17%     -39.1%      72661 ~ 1%  TOTAL softirqs.SCHED
      1985 ~13%     -24.3%       1502 ~19%  TOTAL slabinfo.kmalloc-128.active_objs
      2139 ~20%     -28.4%       1532 ~ 4%  TOTAL proc-vmstat.nr_alloc_batch
    124360 ~33%     -31.0%      85748 ~ 2%  TOTAL softirqs.RCU
      1977 ~ 9%     -18.5%       1610 ~ 9%  TOTAL slabinfo.UDP.active_objs
      1977 ~ 9%     -18.5%       1610 ~ 9%  TOTAL slabinfo.UDP.num_objs
      2066 ~ 6%     -12.9%       1800 ~ 7%  TOTAL slabinfo.kmalloc-128.num_objs
      1738 ~10%     -18.4%       1418 ~ 9%  TOTAL slabinfo.UDPv6.active_objs
      1738 ~10%     -18.4%       1418 ~ 9%  TOTAL slabinfo.UDPv6.num_objs
       923 ~10%     -17.7%        760 ~ 8%  TOTAL slabinfo.TCPv6.active_objs
       923 ~10%     -17.7%        760 ~ 8%  TOTAL slabinfo.TCPv6.num_objs
       989 ~ 9%     -17.1%        820 ~ 7%  TOTAL slabinfo.TCP.active_objs
       989 ~ 9%     -17.1%        820 ~ 7%  TOTAL slabinfo.TCP.num_objs
    398761 ~44%     -32.6%     268792 ~ 3%  TOTAL numa-vmstat.node2.numa_hit
    389672 ~49%     -32.9%     261443 ~ 3%  TOTAL numa-vmstat.node0.numa_hit
       447 ~ 1%     -13.8%        385 ~ 0%  TOTAL vmstat.system.cs

Note: the "~ XX%" numbers are stddev percent.

                              netperf.Throughput_Mbps

     4 *+-*--*--*--*-*--*--*--*--*--*--*--*-*--*--*--*--*--*--*--*-*--*--*--*
       |                                                                    |
       |                                                                    |
   3.5 ++                                                                   |
       |                                                                    |
       |                                                                    |
       |                                                                    |
     3 ++                                                                   |
       |                                                                    |
       |                                                                    |
   2.5 ++                                                                   |
       |                                                                    |
       |                                                                    |
       |                                                                    |
     2 O+-O--O--O--O-O--O--O--O--O--O--O--O-O--O--O--O--O--O--O-------------+

                                 vmstat.system.cs

   460 ++------------------------*--*----------------*----------------------+
       |       .*..    .*..     :    +              +              *..     .*
   450 ++    *.     .*.    *..  :     +    .*..*.. +    *..*..*.. +     .*. |
   440 *+   :      *           :       *..*       *              *    *.    |
       |:   :                 *                                             |
   430 ++: :                                                                |
   420 ++: :                                                                |
       |  *                                                                 |
   410 ++                                                                   |
   400 ++                                                                   |
       |                                                                    |
   390 ++            O        O             O     O        O                |
   380 O+ O  O  O       O  O     O  O  O  O    O     O  O     O             |
       |           O                                                        |
   370 ++-------------------------------------------------------------------+