runtime/pprof: test timed out in StartCPUProfile on darwin-amd64-race

[bcmills]

#!watchflakes
post <- pkg == "runtime/pprof" && log ~ `Test killed with quit` && log ~ `^runtime/pprof\.StartCPUProfile`

https://build.golang.org/log/e7671b5aac25301376187c735141b1a0dd33bbe0 (from #57995 (comment)):

SIGQUIT: quit
PC=0x7ff81b7a62be m=1 sigcode=0
…
goroutine 2 [running]:
	goroutine running on other thread; stack unavailable
created by runtime.init.6 in goroutine 1
	/tmp/buildlet/go/src/runtime/proc.go:310 +0x1a
…
goroutine 55 [running]:
	goroutine running on other thread; stack unavailable
created by testing.(*T).Run in goroutine 1
	/tmp/buildlet/go/src/testing/testing.go:1648 +0x836
…
goroutine 57 [syscall]:
runtime.notetsleepg(0x10bce3a?, 0xc000050ec8?)
	/tmp/buildlet/go/src/runtime/lock_sema.go:294 +0x31 fp=0xc000050e90 sp=0xc000050e48 pc=0x105c711
runtime.(*profBuf).read(0xc000138090, 0x0)
	/tmp/buildlet/go/src/runtime/profbuf.go:500 +0xa8 fp=0xc000050ee8 sp=0xc000050e90 pc=0x10978a8
runtime/pprof.readProfile()
	/tmp/buildlet/go/src/runtime/cpuprof.go:230 +0x4b fp=0xc000050f48 sp=0xc000050ee8 pc=0x10b6f4b
runtime/pprof.profileWriter({0x12eea60, 0xc000414000})
	/tmp/buildlet/go/src/runtime/pprof/pprof.go:810 +0x65 fp=0xc000050fb0 sp=0xc000050f48 pc=0x121d105
runtime/pprof.StartCPUProfile.func2()
	/tmp/buildlet/go/src/runtime/pprof/pprof.go:794 +0x45 fp=0xc000050fe0 sp=0xc000050fb0 pc=0x121d005
runtime.goexit()
	/tmp/buildlet/go/src/runtime/asm_amd64.s:1650 +0x1 fp=0xc000050fe8 sp=0xc000050fe0 pc=0x10bd041
created by runtime/pprof.StartCPUProfile in goroutine 55
	/tmp/buildlet/go/src/runtime/pprof/pprof.go:794 +0x1af
…
*** Test killed with quit: ran too long (4m0s).
FAIL	runtime/pprof	240.037s

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime/pprof" && log ~ `Test killed with quit` && log ~ `^runtime/pprof\.StartCPUProfile`

2023-05-03 18:47 darwin-amd64-race go@ea9097c9 runtime/pprof (log)

SIGQUIT: quit
PC=0x7ff81b7a62be m=1 sigcode=0

goroutine 2 [running]:
	goroutine running on other thread; stack unavailable
created by runtime.init.6 in goroutine 1
	/tmp/buildlet/go/src/runtime/proc.go:310 +0x1a

goroutine 55 [running]:
	goroutine running on other thread; stack unavailable
...
r12    0x700000ea16a8
r13    0x0
r14    0x0
r15    0x700000ea1df0
rip    0x7ff81b7a62be
rflags 0x247
cs     0x7
fs     0x0
gs     0x0
*** Test killed with quit: ran too long (4m0s).

— watchflakes

[mknyszek]

Related to #59995?

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime/pprof" && log ~ `Test killed with quit` && log ~ `^runtime/pprof\.StartCPUProfile`

2023-05-19 18:01 darwin-amd64-race go@b60db8f7 runtime/pprof (log)

SIGQUIT: quit
PC=0x7ff80031e3ea m=1 sigcode=0

goroutine 26 [running]:
	goroutine running on other thread; stack unavailable
created by testing.(*T).Run in goroutine 1
	/tmp/buildlet/go/src/testing/testing.go:1648 +0x82b

rax    0x104
rbx    0x70000188e000
rcx    0x70000188dc48
rdx    0x2b00
rdi    0xc000040388
rsi    0x187c0100187d00
rbp    0x70000188dcf0
rsp    0x70000188dc48
r8     0x0
r9     0xa0
r10    0x0
r11    0x246
r12    0x16
r13    0x0
r14    0x187c0100187d00
r15    0x2b00
rip    0x7ff80031e3ea
rflags 0x247
cs     0x7
fs     0x0
gs     0x0
*** Test killed with quit: ran too long (4m0s).

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime/pprof" && log ~ `Test killed with quit` && log ~ `^runtime/pprof\.StartCPUProfile`

2023-05-24 14:43 darwin-amd64-race go@d9fd19a7 runtime/pprof (log)

SIGQUIT: quit
PC=0x7ff81f9d62be m=1 sigcode=0

goroutine 2 [running]:
	goroutine running on other thread; stack unavailable
created by runtime.init.6 in goroutine 1
	/tmp/buildlet/go/src/runtime/proc.go:310 +0x1a

goroutine 50 [running]:
	goroutine running on other thread; stack unavailable
...
r12    0x7000007b26a8
r13    0x0
r14    0x0
r15    0x7000007b2df0
rip    0x7ff81f9d62be
rflags 0x247
cs     0x7
fs     0x0
gs     0x0
*** Test killed with quit: ran too long (4m0s).

— watchflakes