go-perftuner

Transcript

1. go-perftuner WARSAW, APR 25 2019 Oleg Kovalov Allegro Twitter: oleg_kovalov Github: cristaloleg
2. Me
3. What is a performance optimization?
4. What is a performance optimization?
5. What is a performance optimization?
6. What is a performance optimization?
7. What is a performance optimization?
8. What is a performance optimization?
9. When performance optimization is needed?
10. When performance optimization is needed?
11. When performance optimization is needed?
12. When performance optimization is needed?
13. When performance optimization is needed?
14. When performance optimization is needed?
15. When performance optimization is needed?
16. When performance optimization is needed?
17. When performance optimization isn’t needed?
18. When performance optimization isn’t needed?
19. When performance optimization isn’t needed?
20. When performance optimization isn’t needed?
21. When performance optimization isn’t needed?
22. When performance optimization isn’t needed?
23. When performance optimization isn’t needed?
24. Types of performance tuning
25. Types of performance tuning
26. Types of performance tuning
27. Types of performance tuning
28. Types of performance tuning
29. Types of performance tuning
30. Types of performance tuning
31. Types of performance tuning
32. Types of performance tuning
33. What Go compiler can do?
34. What Go compiler can do?
35. What Go compiler can do?
36. What Go compiler can do?
37. So, welcome go-perftuner
38. So, welcome go-perftuner
39. So, welcome go-perftuner
40. So, welcome go-perftuner
41. So, welcome go-perftuner
42. So, welcome go-perftuner
43. Code inlining
44. Code inlining
45. Code inlining
46. Code inlining
47. Code inlining
48. func ReadRuneSimple(s string) (ch rune, size int) { if len(s) == 0 { return } ch, size = utf8.DecodeRuneInString(s) return } almostInlined example (1)
49. func ReadRuneSimple(s string) (ch rune, size int) { if len(s) == 0 { return } ch, size = utf8.DecodeRuneInString(s) return } $ go-perftuner inl -threshold=100 old.go almostInlined example (1)
50. func ReadRuneSimple(s string) (ch rune, size int) { if len(s) == 0 { return } ch, size = utf8.DecodeRuneInString(s) return } $ go-perftuner inl -threshold=100 old.go $ almostInlined example (1)
51. func ReadRuneLogged(s string) (ch rune, size int) { if len(s) == 0 { return } log.Printf("we're working") ch, size = utf8.DecodeRuneInString(s) return } $ go-perftuner inl -threshold=100 new.go almostInlined example (2)
52. func ReadRuneLogged(s string) (ch rune, size int) { if len(s) == 0 { return } log.Printf("we're working") ch, size = utf8.DecodeRuneInString(s) return } $ go-perftuner inl -threshold=100 new.go inl: ./new.go:34:6: ReadRuneLogged: budget exceeded by 50 almostInlined example (2)
53. Bounds-checking elimination
54. Bounds-checking elimination
55. Bounds-checking elimination
56. Bounds-checking elimination
57. boundChecks example (1) func PutUint32(b []byte, v uint32) { b[0] = byte(v) b[1] = byte(v >> 8) b[2] = byte(v >> 16) b[3] = byte(v >> 24) }
58. boundChecks example (2) func PutUint32(b []byte, v uint32) { b[0] = byte(v) b[1] = byte(v >> 8) b[2] = byte(v >> 16) b[3] = byte(v >> 24) } $ go-perftuner bce old.go bce: ./old.go:4:7: slice/array has bound checks bce: ./old.go:5:7: slice/array has bound checks bce: ./old.go:6:7: slice/array has bound checks bce: ./old.go:7:7: slice/array has bound checks $
59. func PutUint32(b []byte, v uint32) { _ = b[3] // early check to guarantee safety b[0] = byte(v) b[1] = byte(v >> 8) b[2] = byte(v >> 16) b[3] = byte(v >> 24) } boundChecks example (3)
60. boundChecks example (4) func PutUint32(b []byte, v uint32) { _ = b[3] // early check to guarantee safety b[0] = byte(v) b[1] = byte(v >> 8) b[2] = byte(v >> 16) b[3] = byte(v >> 24) } $ go-perftuner bce new.go bce: ./new.go:4:7: slice/array has bound checks $
61. boundChecks example (4) func PutUint32(b []byte, v uint32) { if len(b) < 4 { return } b[0] = byte(v) b[1] = byte(v >> 8) b[2] = byte(v >> 16) b[3] = byte(v >> 24) } $ go-perftuner bce new.go $
62. Escape analysis
63. Escape analysis
64. Escape analysis
65. Escape analysis
66. func getRands(size int) []int { nums := make([]int, size) for i := range nums { nums[i] = rand.Int() } return nums } escapedVariable example (1)
67. func getRands(size int) []int { nums := make([]int, size) for i := range nums { nums[i] = rand.Int() } return nums } $ go-perftuner esc old.go esc: ./old.go:16:14: make([]int, size) $ escapedVariable example (1)
68. func sumRand() (total int) { nums := make([]int, 8191) for i := range nums { nums[i] = rand.Int() } for _, x := range nums { total += x } return total } escapedVariable example (2)
69. func sumRand() (total int) { nums := make([]int, 8191) for i := range nums { nums[i] = rand.Int() } for _, x := range nums { total += x } return total } $ go-perftuner esc 1.go $ escapedVariable example (3)
70. func sumRand() (total int) { nums := make([]int, 8191 + 1) for i := range nums { nums[i] = rand.Int() } for _, x := range nums { total += x } return total } $ go-perftuner esc 1.go escapedVariable example (4)
71. func sumRand() (total int) { nums := make([]int, 8191 + 1) for i := range nums { nums[i] = rand.Int() } for _, x := range nums { total += x } return total } $ go-perftuner esc 1.go esc: ./old.go:16:14: make([]int, 8191 + 1) $ escapedVariable example (4)
72. A very handy tool
73. A very handy tool
74. A very handy tool
75. A very handy tool
76. $ go get golang.org/x/perf/cmd/benchstat $ go test -bench=. -count 10 > old.txt benchstat
77. $ go get golang.org/x/perf/cmd/benchstat $ go test -bench=. -count 10 > old.txt $ # < do some coding and magic with go-perftuner > $ go test -bench=. -count 10 > new.txt benchstat
78. benchstat $ go get golang.org/x/perf/cmd/benchstat $ go test -bench=. -count 10 > old.txt $ # < do some coding and magic with go-perftuner > $ go test -bench=. -count 10 > new.txt $ benchstat old.txt new.txt name old time/op new time/op delta Foo 13.6ms ± 1% 11.8ms ± 1% -13.31% (p=0.016 n=4+5) Bar 32.1ms ± 1% 31.8ms ± 1% ~ (p=0.286 n=4+5)
79. Performance tuning summary
80. Performance tuning summary
81. Performance tuning summary
82. Performance tuning summary
83. Performance tuning summary
84. Performance tuning summary
85. That’s all folks