runtime: STW GC stops working #34736
Description
What version of Go are you using (go version)?
tip (cfe2320)
Does this issue reproduce with the latest release?
No. Go 1.13 works fine.
What operating system and processor architecture are you using (go env)?
darwin/amd64, linux/amd64
What did you do?
$ GODEBUG=gcstoptheworld=1 go tool compile hello.go
The compiler is just used as an example. This happens with essentially any non-trivial Go program. Setting GOGC=1 makes it happens more likely.
What did you expect to see?
Runs successfully.
What did you see instead?
$ GODEBUG=gcstoptheworld=1 go tool compile hello.go
runtime: checkdead: find g 1 in status 1
fatal error: checkdead: runnable g
runtime stack:
runtime.throw(0x1a23d16, 0x15)
/Users/cherryyz/src/go-tip/src/runtime/panic.go:774 +0x72
runtime.checkdead()
/Users/cherryyz/src/go-tip/src/runtime/proc.go:4273 +0x3a6
runtime.mput(...)
/Users/cherryyz/src/go-tip/src/runtime/proc.go:4664
runtime.stopm()
/Users/cherryyz/src/go-tip/src/runtime/proc.go:1963 +0x95
runtime.findrunnable(0xc000022500, 0x0)
/Users/cherryyz/src/go-tip/src/runtime/proc.go:2428 +0x536
runtime.schedule()
/Users/cherryyz/src/go-tip/src/runtime/proc.go:2561 +0x2be
runtime.park_m(0xc00047a000)
/Users/cherryyz/src/go-tip/src/runtime/proc.go:2647 +0x9d
runtime.mcall(0x80000)
/Users/cherryyz/src/go-tip/src/runtime/asm_amd64.s:318 +0x5b
goroutine 1 [runnable]:
cmd/compile/internal/gc.initssaconfig()
/Users/cherryyz/src/go-tip/src/cmd/compile/internal/gc/ssa.go:63 +0x308
cmd/compile/internal/gc.Main(0x1a3baa8)
/Users/cherryyz/src/go-tip/src/cmd/compile/internal/gc/main.go:666 +0x2f94
main.main()
/Users/cherryyz/src/go-tip/src/cmd/compile/main.go:51 +0xac
cc @aclements