net: BenchmarkUDP6LinkLocalUnicast hangs #43449
Description
What version of Go are you using (go version)?
go version devel +95ce805d14 Thu Dec 31 02:24:55 2020 +0000 darwin/amd64
Does this issue reproduce with the latest release?
Yes: tip, 1.15, and 1.14, and maybe older.
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GO111MODULE="" GOARCH="amd64" GOBIN="/Users/josh/bin" GOCACHE="/Users/josh/Library/Caches/go-build" GOENV="/Users/josh/Library/Application Support/go/env" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOINSECURE="" GOMODCACHE="/Users/josh/pkg/mod" GONOPROXY="" GONOSUMDB="" GOOS="darwin" GOPATH="/Users/josh" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/Users/josh/go/tip" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/Users/josh/go/tip/pkg/tool/darwin_amd64" GOVCS="" GOVERSION="devel +95ce805d14 Thu Dec 31 02:24:55 2020 +0000" GCCGO="gccgo" AR="ar" CC="clang" CXX="clang++" CGO_ENABLED="1" GOMOD="/Users/josh/go/tip/src/go.mod" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/1t/n61cbvls5bl293bbb0zyypqw0000gn/T/go-build79030191=/tmp/go-build -gno-record-gcc-switches -fno-common"
What did you do?
$ go test -bench=BenchmarkUDP6LinkLocalUnicast -run=NONE net
What did you expect to see?
Benchmark results.
What did you see instead?
Hang.
SIGQUIT says:
^\SIGQUIT: quit
PC=0x7fff692d4882 m=0 sigcode=0
goroutine 0 [idle]:
runtime.pthread_cond_wait(0x143d9b8, 0x143d978, 0x7fff00000000)
/Users/josh/go/tip/src/runtime/sys_darwin.go:428 +0x39
runtime.semasleep(0xffffffffffffffff, 0x7ffe00000000)
/Users/josh/go/tip/src/runtime/os_darwin.go:63 +0x8d
runtime.notesleep(0x143d770)
/Users/josh/go/tip/src/runtime/lock_sema.go:181 +0xdb
runtime.mPark()
/Users/josh/go/tip/src/runtime/proc.go:1273 +0x39
runtime.stopm()
/Users/josh/go/tip/src/runtime/proc.go:2186 +0x92
runtime.findrunnable(0xc000028000, 0x0)
/Users/josh/go/tip/src/runtime/proc.go:2845 +0x72e
runtime.schedule()
/Users/josh/go/tip/src/runtime/proc.go:3054 +0x2d7
runtime.park_m(0xc000102a80)
/Users/josh/go/tip/src/runtime/proc.go:3203 +0x9d
runtime.mcall(0x106f936)
/Users/josh/go/tip/src/runtime/asm_amd64.s:323 +0x5b
goroutine 1 [chan receive]:
testing.(*B).run1(0xc000014240, 0xc000014240)
/Users/josh/go/tip/src/testing/benchmark.go:234 +0xa5
testing.(*B).Run(0xc000182480, 0x12b0274, 0x1d, 0x12b9638, 0x10e6400)
/Users/josh/go/tip/src/testing/benchmark.go:667 +0x373
testing.runBenchmarks.func1(0xc000182480)
/Users/josh/go/tip/src/testing/benchmark.go:541 +0x78
testing.(*B).runN(0xc000182480, 0x1)
/Users/josh/go/tip/src/testing/benchmark.go:192 +0xeb
testing.runBenchmarks(0x12a64ab, 0x3, 0xc0001a00f0, 0x14323a0, 0x1a, 0x1a, 0x143d020)
/Users/josh/go/tip/src/testing/benchmark.go:550 +0x3d1
testing.(*M).Run(0xc0001d2000, 0x0)
/Users/josh/go/tip/src/testing/testing.go:1424 +0x51d
net.TestMain(0xc0001d2000)
/Users/josh/go/tip/src/net/main_test.go:52 +0x39
main.main()
_testmain.go:575 +0x165
goroutine 36 [IO wait]:
internal/poll.runtime_pollWait(0x8c8e5b0, 0x72, 0x0)
/Users/josh/go/tip/src/runtime/netpoll.go:222 +0x55
internal/poll.(*pollDesc).wait(0xc0001d3398, 0x72, 0x0, 0x1, 0x0)
/Users/josh/go/tip/src/internal/poll/fd_poll_runtime.go:87 +0x45
internal/poll.(*pollDesc).waitRead(...)
/Users/josh/go/tip/src/internal/poll/fd_poll_runtime.go:92
internal/poll.(*FD).ReadFrom(0xc0001d3380, 0xc000018307, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0)
/Users/josh/go/tip/src/internal/poll/fd_unix.go:222 +0x1e6
net.(*netFD).readFrom(0xc0001d3380, 0xc000018307, 0x1, 0x1, 0xc00004ed60, 0x1187776, 0xc0001d3300, 0xc000018307, 0x1)
/Users/josh/go/tip/src/net/fd_posix.go:61 +0x5b
net.(*UDPConn).readFrom(0xc000196020, 0xc000018307, 0x1, 0x1, 0x1, 0x0, 0x0, 0x100fab8)
/Users/josh/go/tip/src/net/udpsock_posix.go:47 +0x6a
net.(*UDPConn).ReadFrom(0xc000196020, 0xc000018307, 0x1, 0x1, 0x12f8720, 0xc000184f30, 0x1, 0x0, 0x0)
/Users/josh/go/tip/src/net/udpsock.go:118 +0x5d
net.BenchmarkUDP6LinkLocalUnicast(0xc000014240)
/Users/josh/go/tip/src/net/udpsock_test.go:48 +0x598
testing.(*B).runN(0xc000014240, 0x1)
/Users/josh/go/tip/src/testing/benchmark.go:192 +0xeb
testing.(*B).run1.func1(0xc000014240)
/Users/josh/go/tip/src/testing/benchmark.go:232 +0x57
created by testing.(*B).run1
/Users/josh/go/tip/src/testing/benchmark.go:225 +0x7f
rax 0x104
rbx 0x2
rcx 0x7ffeefbff2f8
rdx 0x1100
rdi 0x143d9b8
rsi 0x110100001200
rbp 0x7ffeefbff390
rsp 0x7ffeefbff2f8
r8 0x0
r9 0xa0
r10 0x0
r11 0x202
r12 0x143d9b8
r13 0x16
r14 0x110100001200
r15 0xb7dadc0
rip 0x7fff692d4882
rflags 0x203
cs 0x7
fs 0x0
gs 0x0
exit status 2
FAIL net 22.978s