runtime: TestStackGrowthCallback failures

[gopherbot]

#!watchflakes
post <- pkg == "runtime" && test == "TestStackGrowthCallback"

Issue created automatically to collect these failures.

Example (log):

panic: test timed out after 50m0s
running tests:
	TestStackGrowthCallback (46m8s)

runtime.gopark(0x1483fd8?, 0x1748c20?, 0x12?, 0x19?, 0x4?)
	/tmp/buildlet/go/src/runtime/proc.go:398 +0x10e fp=0xc000c2c680 sp=0xc000c2c660 pc=0x104192e
runtime.goparkunlock(...)
	/tmp/buildlet/go/src/runtime/proc.go:404
runtime.semacquire1(0xc000927d38, 0x0?, 0x1, 0x0, 0x12?)
	/tmp/buildlet/go/src/runtime/sema.go:160 +0x258 fp=0xc000c2c6e8 sp=0xc000c2c680 pc=0x1053658
sync.runtime_Semacquire(0xc000927d38?)
	/tmp/buildlet/go/src/runtime/sema.go:62 +0x30 fp=0xc000c2c720 sp=0xc000c2c6e8 pc=0x107a150
sync.(*WaitGroup).Wait(0xc000927d30?)
	/tmp/buildlet/go/src/sync/waitgroup.go:116 +0x54 fp=0xc000c2c748 sp=0xc000c2c720 pc=0x10878b4
runtime_test.TestStackGrowthCallback(0xc000402ea0?)
	/tmp/buildlet/go/src/runtime/stack_test.go:221 +0x12f fp=0xc000c2c770 sp=0xc000c2c748 pc=0x137f54f
testing.tRunner(0xc000402ea0, 0x14837c8)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime" && test == "TestStackGrowthCallback"

2023-05-23 11:37 darwin-amd64-longtest go@f81c8858 runtime.TestStackGrowthCallback (log)

panic: test timed out after 50m0s
running tests:
	TestStackGrowthCallback (46m8s)

runtime.gopark(0x1483fd8?, 0x1748c20?, 0x12?, 0x19?, 0x4?)
	/tmp/buildlet/go/src/runtime/proc.go:398 +0x10e fp=0xc000c2c680 sp=0xc000c2c660 pc=0x104192e
runtime.goparkunlock(...)
	/tmp/buildlet/go/src/runtime/proc.go:404
runtime.semacquire1(0xc000927d38, 0x0?, 0x1, 0x0, 0x12?)
	/tmp/buildlet/go/src/runtime/sema.go:160 +0x258 fp=0xc000c2c6e8 sp=0xc000c2c680 pc=0x1053658
sync.runtime_Semacquire(0xc000927d38?)
	/tmp/buildlet/go/src/runtime/sema.go:62 +0x30 fp=0xc000c2c720 sp=0xc000c2c6e8 pc=0x107a150
sync.(*WaitGroup).Wait(0xc000927d30?)
	/tmp/buildlet/go/src/sync/waitgroup.go:116 +0x54 fp=0xc000c2c748 sp=0xc000c2c720 pc=0x10878b4
runtime_test.TestStackGrowthCallback(0xc000402ea0?)
	/tmp/buildlet/go/src/runtime/stack_test.go:221 +0x12f fp=0xc000c2c770 sp=0xc000c2c748 pc=0x137f54f
testing.tRunner(0xc000402ea0, 0x14837c8)

— watchflakes

[mknyszek]

Looking more closely at this issue, I just realized this is failing in the mayMoreStack section. In fact, this hang looks a lot like the failures in #55160 in general. For instance, there's clearly a runnable goroutine sitting there, likely for the entire duration of the deadlock, which suggests a failure of work conservation in the Go scheduler (as @prattmic discovered).

[mknyszek]

I'm not certain why watchflakes opened a new issue here given that this happened in the mayMoreStack section, but I definitely think this is a duplicate of #55160.