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runtime: revert "do not call timeBeginPeriod on windows"

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This reverts commit ab4c9298b8.

Sysmon critically depends on system timer resolution for retaking
of Ps blocked in system calls. See #14790 for an example
of a program where execution time goes from 2ms to 30ms if
timeBeginPeriod(1) is not used.

We can remove timeBeginPeriod(1) when we support UMS (#7876).

Update #14790

Change-Id: I362b56154359b2c52d47f9f2468fe012b481cf6d
Reviewed-on: https://go-review.googlesource.com/20834
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
This commit is contained in:
Dmitry Vyukov 2016-03-18 10:56:23 +01:00
parent 9d4efdfd12
commit 0435e88a11
4 changed files with 25 additions and 59 deletions
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66
src/runtime/syscall_windows_test.go
View file

@ -622,6 +622,13 @@ uintptr_t cfunc(callback f, uintptr_t n) {
}
}
func TestTimeBeginPeriod(t *testing.T) {
const TIMERR_NOERROR = 0
if *runtime.TimeBeginPeriodRetValue != TIMERR_NOERROR {
t.Fatalf("timeBeginPeriod failed: it returned %d", *runtime.TimeBeginPeriodRetValue)
}
}
// removeOneCPU removes one (any) cpu from affinity mask.
// It returns new affinity mask.
func removeOneCPU(mask uintptr) (uintptr, error) {
@ -874,21 +881,10 @@ var (
modwinmm = syscall.NewLazyDLL("winmm.dll")
modkernel32 = syscall.NewLazyDLL("kernel32.dll")
proctimeBeginPeriod = modwinmm.NewProc("timeBeginPeriod")
proctimeEndPeriod = modwinmm.NewProc("timeEndPeriod")
procCreateEvent = modkernel32.NewProc("CreateEventW")
procSetEvent = modkernel32.NewProc("SetEvent")
)
func timeBeginPeriod(period uint32) {
syscall.Syscall(proctimeBeginPeriod.Addr(), 1, uintptr(period), 0, 0)
}
func timeEndPeriod(period uint32) {
syscall.Syscall(proctimeEndPeriod.Addr(), 1, uintptr(period), 0, 0)
}
func createEvent() (syscall.Handle, error) {
r0, _, e0 := syscall.Syscall6(procCreateEvent.Addr(), 4, 0, 0, 0, 0, 0, 0)
if r0 == 0 {
@ -905,7 +901,7 @@ func setEvent(h syscall.Handle) error {
return nil
}
func benchChanToSyscallPing(b *testing.B) {
func BenchmarkChanToSyscallPing(b *testing.B) {
n := b.N
ch := make(chan int)
event, err := createEvent()
@ -927,17 +923,7 @@ func benchChanToSyscallPing(b *testing.B) {
}
}
func BenchmarkChanToSyscallPing1ms(b *testing.B) {
timeBeginPeriod(1)
benchChanToSyscallPing(b)
timeEndPeriod(1)
}
func BenchmarkChanToSyscallPing15ms(b *testing.B) {
benchChanToSyscallPing(b)
}
func benchSyscallToSyscallPing(b *testing.B) {
func BenchmarkSyscallToSyscallPing(b *testing.B) {
n := b.N
event1, err := createEvent()
if err != nil {
@ -965,17 +951,7 @@ func benchSyscallToSyscallPing(b *testing.B) {
}
}
func BenchmarkSyscallToSyscallPing1ms(b *testing.B) {
timeBeginPeriod(1)
benchSyscallToSyscallPing(b)
timeEndPeriod(1)
}
func BenchmarkSyscallToSyscallPing15ms(b *testing.B) {
benchSyscallToSyscallPing(b)
}
func benchChanToChanPing(b *testing.B) {
func BenchmarkChanToChanPing(b *testing.B) {
n := b.N
ch1 := make(chan int)
ch2 := make(chan int)
@ -991,28 +967,8 @@ func benchChanToChanPing(b *testing.B) {
}
}
func BenchmarkChanToChanPing1ms(b *testing.B) {
timeBeginPeriod(1)
benchChanToChanPing(b)
timeEndPeriod(1)
}
func BenchmarkChanToChanPing15ms(b *testing.B) {
benchChanToChanPing(b)
}
func benchOsYield(b *testing.B) {
func BenchmarkOsYield(b *testing.B) {
for i := 0; i < b.N; i++ {
runtime.OsYield()
}
}
func BenchmarkOsYield1ms(b *testing.B) {
timeBeginPeriod(1)
benchOsYield(b)
timeEndPeriod(1)
}
func BenchmarkOsYield15ms(b *testing.B) {
benchOsYield(b)
}