From 6f4ae360a5242eb3554ab4d3695529a1c60c04da Mon Sep 17 00:00:00 2001 From: Darren Stahl Date: Tue, 9 Jan 2018 14:51:36 -0800 Subject: [PATCH] Remove workaround to perf issues in go1.6 Starting in go1.9, Golang lowers the timer frequency when not required reducing CPU usage. This workaround prevents Golang from doing so, and since the initial issue was fixed, I see no perf regressions. This does not need to be conditional based on Golang verison, as the issue being worked around was only in go1.6. Signed-off-by: Darren Stahl --- file.go | 3 --- zsyscall_windows.go | 8 -------- 2 files changed, 11 deletions(-) diff --git a/file.go b/file.go index 57ac369..4334ff1 100644 --- a/file.go +++ b/file.go @@ -16,7 +16,6 @@ import ( //sys createIoCompletionPort(file syscall.Handle, port syscall.Handle, key uintptr, threadCount uint32) (newport syscall.Handle, err error) = CreateIoCompletionPort //sys getQueuedCompletionStatus(port syscall.Handle, bytes *uint32, key *uintptr, o **ioOperation, timeout uint32) (err error) = GetQueuedCompletionStatus //sys setFileCompletionNotificationModes(h syscall.Handle, flags uint8) (err error) = SetFileCompletionNotificationModes -//sys timeBeginPeriod(period uint32) (n int32) = winmm.timeBeginPeriod type atomicBool int32 @@ -153,8 +152,6 @@ func (f *win32File) prepareIo() (*ioOperation, error) { // ioCompletionProcessor processes completed async IOs forever func ioCompletionProcessor(h syscall.Handle) { - // Set the timer resolution to 1. This fixes a performance regression in golang 1.6. - timeBeginPeriod(1) for { var bytes uint32 var key uintptr diff --git a/zsyscall_windows.go b/zsyscall_windows.go index 4f7a52e..3f52763 100644 --- a/zsyscall_windows.go +++ b/zsyscall_windows.go @@ -38,14 +38,12 @@ func errnoErr(e syscall.Errno) error { var ( modkernel32 = windows.NewLazySystemDLL("kernel32.dll") - modwinmm = windows.NewLazySystemDLL("winmm.dll") modadvapi32 = windows.NewLazySystemDLL("advapi32.dll") procCancelIoEx = modkernel32.NewProc("CancelIoEx") procCreateIoCompletionPort = modkernel32.NewProc("CreateIoCompletionPort") procGetQueuedCompletionStatus = modkernel32.NewProc("GetQueuedCompletionStatus") procSetFileCompletionNotificationModes = modkernel32.NewProc("SetFileCompletionNotificationModes") - proctimeBeginPeriod = modwinmm.NewProc("timeBeginPeriod") procConnectNamedPipe = modkernel32.NewProc("ConnectNamedPipe") procCreateNamedPipeW = modkernel32.NewProc("CreateNamedPipeW") procCreateFileW = modkernel32.NewProc("CreateFileW") @@ -122,12 +120,6 @@ func setFileCompletionNotificationModes(h syscall.Handle, flags uint8) (err erro return } -func timeBeginPeriod(period uint32) (n int32) { - r0, _, _ := syscall.Syscall(proctimeBeginPeriod.Addr(), 1, uintptr(period), 0, 0) - n = int32(r0) - return -} - func connectNamedPipe(pipe syscall.Handle, o *syscall.Overlapped) (err error) { r1, _, e1 := syscall.Syscall(procConnectNamedPipe.Addr(), 2, uintptr(pipe), uintptr(unsafe.Pointer(o)), 0) if r1 == 0 {