made list_add sort, slower speed

trace  valid  util     ops      secs  Kops
 0       yes   99%    5694
0.002097  2716
 1       yes  100%    5848  0.001970  2969
 2       yes
99%    6648  0.002434  2731
 3       yes  100%    5380  0.001877  2867

4       yes   66%   14400  0.002620  5496
 5       yes   96%    4800
0.015460   310
 6       yes   95%    4800  0.014973   321
 7       yes
55%   12000  0.099158   121
 8       yes   51%   24000  0.424120    57

9       yes   31%   14401  0.188815    76
10       yes   30%   14401
0.009494  1517
Total          75%  112372  0.763018   147

Perf index =
45 (util) + 6 (thru) = 51/100