Re: GSoC: Add SMT/HT awareness to DragonFlyBSD scheduler

Hello,

Here are some results from a AMD FX(tm)-8150 Eight-Core Processor(thanks
profkmax):

############ enable smt ########
kern.usched_bsd4.smt_enable: 0 -> 1
tps = 32987.010952 (including connections establishing)
tps = 33072.952733 (including connections establishing)
tps = 32693.574568 (including connections establishing)
tps = 33084.277648 (including connections establishing)
tps = 33481.054536 (including connections establishing)
tps = 33013.296931 (including connections establishing)
tps = 32711.982849 (including connections establishing)
tps = 32686.120901 (including connections establishing)
tps = 32792.744933 (including connections establishing)
tps = 33367.284545 (including connections establishing)

############ disable smt ########
kern.usched_bsd4.smt_enable: 1 -> 0
tps = 31364.873850 (including connections establishing)
tps = 31340.974524 (including connections establishing)
tps = 31648.286265 (including connections establishing)
tps = 30913.788400 (including connections establishing)
tps = 31338.052583 (including connections establishing)
tps = 31360.521337 (including connections establishing)
tps = 31545.915474 (including connections establishing)
tps = 31489.008958 (including connections establishing)
tps = 30657.108291 (including connections establishing)
tps = 31294.472379 (including connections establishing)

The difference is > 1500tps (5%).

Here is an interesting CPU topology from a dual-socket XEON:
hw.cpu_topology.tree:
\-PACKAGE MEMBERS: cpu0 cpu1 cpu2 cpu3 cpu4 cpu5 cpu6 cpu7 cpu8 cpu9 cpu10
cpu11 cpu12 cpu13 cpu14 cpu15 cpu16 cpu17 cpu18 cpu19 cpu20 cpu21 cpu22
cpu23
  |-CHIP ID 0: cpu1 cpu3 cpu5 cpu7 cpu9 cpu11 cpu13 cpu15 cpu17 cpu19 cpu21
cpu23
  | |-CORE ID 0: cpu1 cpu13
  | | |-THREAD ID 0: cpu1
  | | \-THREAD ID 1: cpu13
  | |-CORE ID 1: cpu3 cpu15
  | | |-THREAD ID 0: cpu3
  | | \-THREAD ID 1: cpu15
  | |-CORE ID 2: cpu5 cpu17
  | | |-THREAD ID 0: cpu5
  | | \-THREAD ID 1: cpu17
  | |-CORE ID 8: cpu7 cpu19
  | | |-THREAD ID 0: cpu7
  | | \-THREAD ID 1: cpu19
  | |-CORE ID 9: cpu9 cpu21
  | | |-THREAD ID 0: cpu9
  | | \-THREAD ID 1: cpu21
  | \-CORE ID 10: cpu11 cpu23
  |   |-THREAD ID 0: cpu11
  |   \-THREAD ID 1: cpu23
  \-CHIP ID 1: cpu0 cpu2 cpu4 cpu6 cpu8 cpu10 cpu12 cpu14 cpu16 cpu18 cpu20
cpu22
    |-CORE ID 0: cpu0 cpu12
    | |-THREAD ID 0: cpu0
    | \-THREAD ID 1: cpu12
    |-CORE ID 1: cpu2 cpu14
    | |-THREAD ID 0: cpu2
    | \-THREAD ID 1: cpu14
    |-CORE ID 2: cpu4 cpu16
    | |-THREAD ID 0: cpu4
    | \-THREAD ID 1: cpu16
    |-CORE ID 8: cpu6 cpu18
    | |-THREAD ID 0: cpu6
    | \-THREAD ID 1: cpu18
    |-CORE ID 9: cpu8 cpu20
    | |-THREAD ID 0: cpu8
    | \-THREAD ID 1: cpu20
    \-CORE ID 10: cpu10 cpu22
      |-THREAD ID 0: cpu10
      \-THREAD ID 1: cpu22

And here are some tests. The differences are < 5% (but not so much):
############ enable smt ########
kern.usched_bsd4.smt_enable: 0 -> 1
tps = 53019.868091 (including connections establishing)
tps = 52814.820895 (including connections establishing)
tps = 53251.869806 (including connections establishing)
tps = 53914.301869 (including connections establishing)
tps = 53278.858660 (including connections establishing)
tps = 53044.933921 (including connections establishing)
tps = 53758.093953 (including connections establishing)
tps = 53965.776254 (including connections establishing)
tps = 53093.809461 (including connections establishing)
tps = 53322.645105 (including connections establishing)

############ disable smt ########
kern.usched_bsd4.smt_enable: 1 -> 0
tps = 51379.980647 (including connections establishing)
tps = 50960.834688 (including connections establishing)
tps = 51336.041880 (including connections establishing)
tps = 51311.336021 (including connections establishing)
tps = 51227.944502 (including connections establishing)
tps = 50828.181685 (including connections establishing)
tps = 51342.268742 (including connections establishing)
tps = 50887.898412 (including connections establishing)
tps = 50667.897897 (including connections establishing)
tps = 50960.282830 (including connections establishing)