What version of Go are you using (go version)?

$ go version
go version devel +c2edcf4b12 Tue Nov 12 01:09:40 2019 +0000 linux/arm64

Does this issue reproduce with the latest release?

Yes.

What operating system and processor architecture are you using (go env)?

$ go env
GO111MODULE=""
GOARCH="arm64"
GOBIN=""
GOCACHE="/home/xiaji01/.cache/go-build"
GOENV="/home/xiaji01/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="arm64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/xiaji01/.go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/xiaji01/local/go.latest"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/xiaji01/local/go.latest/pkg/tool/linux_arm64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/xiaji01/local/go.latest/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 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build855348932=/tmp/go-build -gno-record-gcc-switches"

What did you do?

build go with 'src/all.bash'

What did you expect to see?

both building and testing pass

What did you see instead?

The following testcases often failed due to time-out (10m), it's likely caused by heavy I/O slowing down the testing the target machine may run up to 200+ cases in parallel, if setting GOMAXPROCS to smaller value the issue is gone (verified by multiple iterations), can we increase the time-out value?

TestStackMem
TestStackGrowth
TestSemaHandoff

=== RUN TestParallelRWMutexReaders
--- PASS: TestParallelRWMutexReaders (0.00s)
=== RUN TestRWMutex
--- PASS: TestRWMutex (0.07s)
=== RUN TestSemaHandoff
panic: test timed out after 10m0s

goroutine 30958094 [running]:
panic(0x203300, 0x4000530000)
/home/xiaji01/local/go.latest/src/runtime/panic.go:1054 +0x404 fp=0x400038bf70 sp=0x400038bec0 pc=0x43704
testing.(*M).startAlarm.func1()
/home/xiaji01/local/go.latest/src/testing/testing.go:1422 +0xc8 fp=0x400038bfd0 sp=0x400038bf70 pc=0xe9158
runtime.goexit()
/home/xiaji01/local/go.latest/src/runtime/asm_arm64.s:1148 +0x4 fp=0x400038bfd0 sp=0x400038bfd0 pc=0x782a4
created by time.goFunc
/home/xiaji01/local/go.latest/src/time/sleep.go:171 +0x40

goroutine 1 [chan receive, 4 minutes, locked to thread]:
runtime.gopark(0x275050, 0x400310d8b8, 0x40002c170e, 0x2)
/home/xiaji01/local/go.latest/src/runtime/proc.go:304 +0xd0 fp=0x40002c1ac0 sp=0x40002c1aa0 pc=0x46230
runtime.chanrecv(0x400310d860, 0x40002c1bd8, 0x4000000101, 0xe57f4)
/home/xiaji01/local/go.latest/src/runtime/chan.go:563 +0x2c4 fp=0x40002c1b50 sp=0x40002c1ac0 pc=0x174f4
runtime.chanrecv1(0x400310d860, 0x40002c1bd8)
/home/xiaji01/local/go.latest/src/runtime/chan.go:433 +0x28 fp=0x40002c1b80 sp=0x40002c1b50 pc=0x171d8
testing.(*T).Run(0x40006125a0, 0x26394d, 0xf, 0x276b20, 0x5dca4701)
/home/xiaji01/local/go.latest/src/testing/testing.go:1006 +0x2e0 fp=0x40002c1c30 sp=0x40002c1b80 pc=0xe5810
testing.runTests.func1(0x4000388000)
/home/xiaji01/local/go.latest/src/testing/testing.go:1247 +0x74 fp=0x40002c1c80 sp=0x40002c1c30 pc=0xe9004