setdiscovery: stop limiting the number of local head we initially send
In our testing this limitation provides now real gain and instead triggers
pathological discovery timing for some repository with many heads.
See inline documentation for details.
Some timing below:
Mozilla try repository, (~1M revs, ~35K heads), discovery between 2 clones with
100 head missing on each side
before:
! wall 1.492111 comb 1.490000 user 1.450000 sys 0.040000 (best of 20)
! wall 1.813992 comb 1.820000 user 1.700000 sys 0.120000 (max of 20)
! wall 1.574326 comb 1.573500 user 1.522000 sys 0.051500 (avg of 20)
! wall 1.572583 comb 1.570000 user 1.520000 sys 0.050000 (median of 20)
after:
! wall 1.147834 comb 1.150000 user 1.090000 sys 0.060000 (best of 20)
! wall 1.449144 comb 1.450000 user 1.330000 sys 0.120000 (max of 20)
! wall 1.204618 comb 1.202500 user 1.146500 sys 0.056000 (avg of 20)
! wall 1.194407 comb 1.190000 user 1.140000 sys 0.050000 (median of 20)
pypy (~100 heads, 317 heads) discovery between clones with only 42 common heads
before:
! wall 0.031653 comb 0.030000 user 0.030000 sys 0.000000 (best of 25)
! wall 0.055719 comb 0.050000 user 0.040000 sys 0.010000 (max of 25)
! wall 0.038939 comb 0.039600 user 0.038400 sys 0.001200 (avg of 25)
! wall 0.038660 comb 0.050000 user 0.040000 sys 0.010000 (median of 25)
after:
! wall 0.018754 comb 0.020000 user 0.020000 sys 0.000000 (best of 49)
! wall 0.034505 comb 0.040000 user 0.030000 sys 0.010000 (max of 49)
! wall 0.019631 comb 0.019796 user 0.018367 sys 0.001429 (avg of 49)
! wall 0.019132 comb 0.020000 user 0.020000 sys 0.000000 (median of 49)
Private repository (~1M revs, ~3K heads), discovery from a strip subset, about
100 changesets to be pulled.
before:
! wall 1.837729 comb 1.840000 user 1.790000 sys 0.050000 (best of 20)
! wall 2.203468 comb 2.200000 user 2.100000 sys 0.100000 (max of 20)
! wall 2.049355 comb 2.048500 user 2.002500 sys 0.046000 (avg of 20)
! wall 2.035315 comb 2.040000 user 2.000000 sys 0.040000 (median of 20)
after:
! wall 0.136598 comb 0.130000 user 0.110000 sys 0.020000 (best of 20)
! wall 0.330519 comb 0.330000 user 0.260000 sys 0.070000 (max of 20)
! wall 0.157254 comb 0.155500 user 0.123000 sys 0.032500 (avg of 20)
! wall 0.149870 comb 0.140000 user 0.110000 sys 0.030000 (median of 20)
Same private repo, discovery between two clone with 500 different heads on each
side:
before:
! wall 2.372919 comb 2.370000 user 2.320000 sys 0.050000 (best of 20)
! wall 2.622422 comb 2.610000 user 2.510000 sys 0.100000 (max of 20)
! wall 2.450135 comb 2.450000 user 2.402000 sys 0.048000 (avg of 20)
! wall 2.443896 comb 2.450000 user 2.410000 sys 0.040000 (median of 20)
after:
! wall 0.625497 comb 0.620000 user 0.570000 sys 0.050000 (best of 20)
! wall 0.834723 comb 0.820000 user 0.730000 sys 0.090000 (max of 20)
! wall 0.675725 comb 0.675500 user 0.628000 sys 0.047500 (avg of 20)
! wall 0.671614 comb 0.680000 user 0.640000 sys 0.040000 (median of 20)
hgrc settings command line options final result
quiet verbo debug quiet verbo debug quiet verbo debug
0 False False False False False False -> False False False
1 True False False False False False -> True False False
2 False True False False False False -> False True False
3 True True False False False False -> False False False
4 False False True False False False -> False True True
5 True False True False False False -> False True True
6 False True True False False False -> False True True
7 True True True False False False -> False True True
8 False False False True False False -> True False False
9 True False False True False False -> True False False
10 False True False True False False -> True False False
11 True True False True False False -> True False False
12 False False True True False False -> True False False
13 True False True True False False -> True False False
14 False True True True False False -> True False False
15 True True True True False False -> True False False
16 False False False False True False -> False True False
17 True False False False True False -> False True False
18 False True False False True False -> False True False
19 True True False False True False -> False True False
20 False False True False True False -> False True False
21 True False True False True False -> False True False
22 False True True False True False -> False True False
23 True True True False True False -> False True False
24 False False False True True False -> False False False
25 True False False True True False -> False False False
26 False True False True True False -> False False False
27 True True False True True False -> False False False
28 False False True True True False -> False False False
29 True False True True True False -> False False False
30 False True True True True False -> False False False
31 True True True True True False -> False False False
32 False False False False False True -> False True True
33 True False False False False True -> False True True
34 False True False False False True -> False True True
35 True True False False False True -> False True True
36 False False True False False True -> False True True
37 True False True False False True -> False True True
38 False True True False False True -> False True True
39 True True True False False True -> False True True
40 False False False True False True -> False True True
41 True False False True False True -> False True True
42 False True False True False True -> False True True
43 True True False True False True -> False True True
44 False False True True False True -> False True True
45 True False True True False True -> False True True
46 False True True True False True -> False True True
47 True True True True False True -> False True True
48 False False False False True True -> False True True
49 True False False False True True -> False True True
50 False True False False True True -> False True True
51 True True False False True True -> False True True
52 False False True False True True -> False True True
53 True False True False True True -> False True True
54 False True True False True True -> False True True
55 True True True False True True -> False True True
56 False False False True True True -> False True True
57 True False False True True True -> False True True
58 False True False True True True -> False True True
59 True True False True True True -> False True True
60 False False True True True True -> False True True
61 True False True True True True -> False True True
62 False True True True True True -> False True True
63 True True True True True True -> False True True