Closed
Description
What version of Go are you using (go version
)?
tip (16db189)
What operating system and processor architecture are you using (go env
)?
linux/amd64
What did you do?
$ go test -c math
$ ./math.test -test.bench=Lgamma -test.benchtime=10s -test.cpuprofile=/tmp/p
...
$ go tool pprof math.test /tmp/p
File: math.test
Type: cpu
Time: Apr 17, 2017 at 4:37pm (EDT)
Duration: 21.52s, Total samples = 214.20ms ( 1%)
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 214.10ms, 100% of 214.20ms total
Dropped 4 nodes (cum <= 1.07ms)
flat flat% sum% cum cum%
197.10ms 92.02% 92.02% 197.10ms 92.02% math.Lgamma
9.40ms 4.39% 96.41% 214.10ms 100% math_test.BenchmarkLgamma
7.60ms 3.55% 100% 7.60ms 3.55% math.Lgamma
0 0% 100% 214.10ms 100% testing.(*B).launch
0 0% 100% 214.10ms 100% testing.(*B).runN
(pprof)
Note that the profile only covers 1%: Duration: 21.52s, Total samples = 214.20ms ( 1%)
.
This is not the case for Go 1.8.
$ go1.8 test -c math
$ ./math.test -test.bench=Lgamma -test.benchtime=10s -test.cpuprofile=/tmp/p18
$ go tool pprof math.test /tmp/p18
File: math.test
Type: cpu
Time: Apr 17, 2017 at 4:39pm (EDT)
Duration: 21.26s, Total samples = 21.27s (100.06%)
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 21270ms, 100% of 21270ms total
flat flat% sum% cum cum%
20560ms 96.66% 96.66% 20560ms 96.66% math.Lgamma
710ms 3.34% 100% 21270ms 100% math_test.BenchmarkLgamma
0 0% 100% 21270ms 100% runtime.goexit
0 0% 100% 21270ms 100% testing.(*B).launch
0 0% 100% 21270ms 100% testing.(*B).runN
(pprof)
Given the default profiling rate is 100, maybe a factor of 100 is missing somewhere?