runtime: TestCgoCallbackGC failing on FreeBSD/arm

[paulzhol]

I've starting running builds with CGO_ENABLED=1 on freebsd-arm-paulzhol and it fails consistently.
System is an ALLWINNER A20 running FreeBSD 11.0-RELEASE-p2. I've noticed CGO_ENABLED was off by default because the bootstrap 1.4.3 compilers need to be built with CGO_ENABLED=0.

ok  	regexp/syntax	4.360s
--- FAIL: TestCgoCallbackGC (180.81s)
	crash_test.go:106: testprogcgo CgoCallbackGC exit status: exit status 2
	crash_cgo_test.go:66: expected "OK\n", but got:
		SIGQUIT: quit
		PC=0x20263cd0 m=0 sigcode=65537
		signal arrived during cgo execution
		
		goroutine 206 [syscall, locked to thread]:
		runtime.cgocall(0xcc158, 0x30acc7d4, 0x10be80b)
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/cgocall.go:131 +0xb4 fp=0x30acc7bc sp=0x30acc7a0
		main._Cfunc_foo()
			_/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/_obj/_cgo_gotypes.go:164 +0x30 fp=0x30acc7d0 sp=0x30acc7bc
		main.CgoCallbackGC.func2(0x30a90d80)
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/callback.go:81 +0x14 fp=0x30acc7e4 sp=0x30acc7d0
		runtime.goexit()
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/asm_arm.s:1017 +0x4 fp=0x30acc7e4 sp=0x30acc7e4
		created by main.CgoCallbackGC
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/callback.go:83 +0xcc
		
		goroutine 1 [chan receive]:
		main.CgoCallbackGC()
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/callback.go:86 +0x104
		main.main()
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/main.go:34 +0x168
		
		goroutine 17 [syscall, locked to thread]:
		runtime.goexit()
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/asm_arm.s:1017 +0x4
		
		goroutine 5 [syscall]:
		os/signal.signal_recv(0x0)
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/sigqueue.go:116 +0x154
		os/signal.loop()
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/os/signal/signal_unix.go:22 +0x14
		created by os/signal.init.1
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/os/signal/signal_unix.go:28 +0x30
		
		goroutine 133 [chan send]:
		main.CgoCallbackGC.func2(0x30a90d80)
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/callback.go:82 +0x38
		created by main.CgoCallbackGC
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/callback.go:83 +0xcc
		
		goroutine 130 [runnable, locked to thread]:
		main._Cfunc_foo()
			_/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/_obj/_cgo_gotypes.go:164 +0x30
		main.CgoCallbackGC.func2(0x30a90d80)
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/callback.go:81 +0x14
		created by main.CgoCallbackGC
			/tmp/gobuilder/freebsd-arm-paulzhol-21a8db1c5fdd/go/src/runtime/testdata/testprogcgo/callback.go:83 +0xcc
		

https://build.golang.org/log/bfcba940a506c85e37f975ac5f707a8e56016a28
https://build.golang.org/log/b6d6763f78183bb51792bc55ce055d1301e7cbbc
https://build.golang.org/log/24b97b0e2513b28f2b8b117ff0028cfc36ea7790

[ianlancetaylor]

This may simply mean that the test program is timing out. What happens if you set GO_TEST_TIMEOUT_SCALE=4 in the environment?

[paulzhol]

Running ./all.bash now, but note that I'm already on GO_TEST_TIMEOUT_SCALE=3 by default.

[ianlancetaylor]

Another thing you can try is

cd src/runtime/testdata/testprogcgo
go build
./testprogcgo CgoCallbackGC

Does that complete, or does it just hang?

[ianlancetaylor]

Note: updated previous comment to pass an argument to ./testprogcgo.

[paulzhol]

GO_TEST_TIMEOUT_SCALE=4 also failed:
build.txt

I've built testprogcgo: testprogcgo_build.txt

It just spins:

[paulzhol]

Update: it exited after roughly 13m with OK, then I ran it again with some strange results:

time ./testprogcgo CgoCallbackGC                                                                        
OK

real    0m44.077s
user    0m57.942s
sys     0m0.681s

time ./testprogcgo CgoCallbackGC
OK

real    7m41.345s
user    1m41.639s
sys     12m46.762s

time ./testprogcgo CgoCallbackGC
OK

real    8m50.200s
user    1m46.821s
sys     14m58.288s

I'll try setting GO_TEST_TIMEOUT_SCALE=6

[ianlancetaylor]

Probably related to #13926.

[paulzhol]

Looks like setting GO_TEST_TIMEOUT_SCALE=16 does the trick, Thanks!