diff options
Diffstat (limited to 'go-patches/highres-timer.patch')
| -rw-r--r-- | go-patches/highres-timer.patch | 395 |
1 files changed, 0 insertions, 395 deletions
diff --git a/go-patches/highres-timer.patch b/go-patches/highres-timer.patch deleted file mode 100644 index 87dd6b17..00000000 --- a/go-patches/highres-timer.patch +++ /dev/null @@ -1,395 +0,0 @@ -From 2975b381dc3f559a2eef875582d73cec00ab6b17 Mon Sep 17 00:00:00 2001 -From: Alex Brainman <alex.brainman@gmail.com> -Date: Sun, 19 Jul 2020 16:06:48 +1000 -Subject: [PATCH] runtime: use CreateWaitableTimerEx to implement usleep - -@jstarks suggested that recent versions of Windows provide access to high resolution timers. See - -https://github.com/golang/go/issues/8687#issuecomment-656259353 - -for details. - -I tried to run this C program on my Windows 10 computer - -``` - #include <stdio.h> - #include <Windows.h> - - #pragma comment(lib, "Winmm.lib") - -// Apparently this is already defined when I use msvc cl. -//#define CREATE_WAITABLE_TIMER_HIGH_RESOLUTION = 0x00000002; - -int usleep(HANDLE timer, LONGLONG d) { - LARGE_INTEGER liDueTime; - DWORD ret; - LARGE_INTEGER StartingTime, EndingTime, ElapsedMicroseconds; - LARGE_INTEGER Frequency; - - QueryPerformanceFrequency(&Frequency); - QueryPerformanceCounter(&StartingTime); - - liDueTime.QuadPart = d; - liDueTime.QuadPart = liDueTime.QuadPart * 10; // us into 100 of ns units - liDueTime.QuadPart = -liDueTime.QuadPart; // negative for relative dure time - - if (!SetWaitableTimer(timer, &liDueTime, 0, NULL, NULL, 0)) { - printf("SetWaitableTimer failed: errno=%d\n", GetLastError()); - return 1; - } - - ret = WaitForSingleObject(timer, INFINITE); - if (ret != WAIT_OBJECT_0) { - printf("WaitForSingleObject failed: ret=%d errno=%d\n", ret, GetLastError()); - return 1; - } - - QueryPerformanceCounter(&EndingTime); - ElapsedMicroseconds.QuadPart = EndingTime.QuadPart - StartingTime.QuadPart; - ElapsedMicroseconds.QuadPart *= 1000000; - ElapsedMicroseconds.QuadPart /= Frequency.QuadPart; - - printf("delay is %lld us - slept for %lld us\n", d, ElapsedMicroseconds.QuadPart); - - return 0; -} - -int testTimer(DWORD createFlag) -{ - HANDLE timer; - - timer = CreateWaitableTimerEx(NULL, NULL, createFlag, TIMER_ALL_ACCESS); - if (timer == NULL) { - printf("CreateWaitableTimerEx failed: errno=%d\n", GetLastError()); - return 1; - } - - usleep(timer, 1000LL); - usleep(timer, 100LL); - usleep(timer, 10LL); - usleep(timer, 1LL); - - CloseHandle(timer); - - return 0; -} - -int main() -{ - printf("\n1. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is off\n"); - testTimer(0); - - printf("\n2. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is off\n"); - testTimer(CREATE_WAITABLE_TIMER_HIGH_RESOLUTION); - - timeBeginPeriod(1); - - printf("\n3. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is on\n"); - testTimer(0); - - printf("\n4. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is on\n"); - testTimer(CREATE_WAITABLE_TIMER_HIGH_RESOLUTION); -} -``` - -and I see this output - -``` -1. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is off -delay is 1000 us - slept for 4045 us -delay is 100 us - slept for 3915 us -delay is 10 us - slept for 3291 us -delay is 1 us - slept for 2234 us - -2. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is off -delay is 1000 us - slept for 1076 us -delay is 100 us - slept for 569 us -delay is 10 us - slept for 585 us -delay is 1 us - slept for 17 us - -3. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is on -delay is 1000 us - slept for 742 us -delay is 100 us - slept for 893 us -delay is 10 us - slept for 414 us -delay is 1 us - slept for 920 us - -4. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is on -delay is 1000 us - slept for 1466 us -delay is 100 us - slept for 559 us -delay is 10 us - slept for 535 us -delay is 1 us - slept for 5 us -``` - -That shows, that indeed using CREATE_WAITABLE_TIMER_HIGH_RESOLUTION -will provide sleeps as low as about 500 microseconds, while our -current approach provides about 1 millisecond sleep. - -New approach also does not require for timeBeginPeriod to be on, -so this change solves long standing problem with go programs draining -laptop battery, because it calls timeBeginPeriod. - -This change will only run on systems where -CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag is available. If not -available, the runtime will fallback to original code that uses -timeBeginPeriod. - -This is how this change affects benchmark reported in issue #14790 - -name old time/op new time/op delta -ChanToSyscallPing 1.05ms ± 2% 0.68ms ±11% -35.43% (p=0.000 n=10+10) - -The benchmark was run with GOMAXPROCS set to 1. - -Fixes #8687 -Updates #14790 - -Change-Id: I5b97ba58289c088c17c05292e12e45285c467eae ---- - -diff --git a/src/runtime/os_windows.go b/src/runtime/os_windows.go -index a62e941..46f4a23 100644 ---- a/src/runtime/os_windows.go -+++ b/src/runtime/os_windows.go -@@ -21,6 +21,7 @@ - //go:cgo_import_dynamic runtime._CreateIoCompletionPort CreateIoCompletionPort%4 "kernel32.dll" - //go:cgo_import_dynamic runtime._CreateThread CreateThread%6 "kernel32.dll" - //go:cgo_import_dynamic runtime._CreateWaitableTimerA CreateWaitableTimerA%3 "kernel32.dll" -+//go:cgo_import_dynamic runtime._CreateWaitableTimerExW CreateWaitableTimerExW%4 "kernel32.dll" - //go:cgo_import_dynamic runtime._DuplicateHandle DuplicateHandle%7 "kernel32.dll" - //go:cgo_import_dynamic runtime._ExitProcess ExitProcess%1 "kernel32.dll" - //go:cgo_import_dynamic runtime._FreeEnvironmentStringsW FreeEnvironmentStringsW%1 "kernel32.dll" -@@ -68,6 +69,7 @@ - _CreateIoCompletionPort, - _CreateThread, - _CreateWaitableTimerA, -+ _CreateWaitableTimerExW, - _DuplicateHandle, - _ExitProcess, - _FreeEnvironmentStringsW, -@@ -151,6 +153,8 @@ - waitsema uintptr // semaphore for parking on locks - resumesema uintptr // semaphore to indicate suspend/resume - -+ highResTimer uintptr // high resolution timer handle used in usleep -+ - // preemptExtLock synchronizes preemptM with entry/exit from - // external C code. - // -@@ -407,6 +411,12 @@ - // if we're already using the CPU, but if all Ps are idle there's no - // need to consume extra power to drive the high-res timer. - func osRelax(relax bool) uint32 { -+ if haveHighResTimer { -+ // Only call timeBeginPeriod/timeEndPeriod, if -+ // high resolution timer is not available. -+ return 0 -+ } -+ - if relax { - return uint32(stdcall1(_timeEndPeriod, 1)) - } else { -@@ -414,6 +424,37 @@ - } - } - -+// haveHighResTimer determines, if CreateWaitableTimerEx -+// CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag is available. -+var haveHighResTimer = false -+ -+// createHighResTimer calls CreateWaitableTimerEx with -+// CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag to create high -+// resolution timer. createHighResTimer returns new timer -+// handle or 0, if CreateWaitableTimerEx failed. -+func createHighResTimer() uintptr { -+ const ( -+ // As per @jstarks, see -+ // https://github.com/golang/go/issues/8687#issuecomment-656259353 -+ _CREATE_WAITABLE_TIMER_HIGH_RESOLUTION = 0x00000002 -+ _TIMER_ALL_ACCESS = 0x1F0003 -+ ) -+ return stdcall4(_CreateWaitableTimerExW, 0, 0, _CREATE_WAITABLE_TIMER_HIGH_RESOLUTION, _TIMER_ALL_ACCESS) -+} -+ -+func initHighResTimer() { -+ if GOARCH == "arm" { -+ // TODO: Not yet implemented. -+ return -+ } -+ h := createHighResTimer() -+ if h != 0 { -+ haveHighResTimer = true -+ usleep2Addr = unsafe.Pointer(funcPC(usleep2HighRes)) -+ stdcall1(_CloseHandle, h) -+ } -+} -+ - func osinit() { - asmstdcallAddr = unsafe.Pointer(funcPC(asmstdcall)) - usleep2Addr = unsafe.Pointer(funcPC(usleep2)) -@@ -429,6 +470,7 @@ - - stdcall2(_SetConsoleCtrlHandler, funcPC(ctrlhandler), 1) - -+ initHighResTimer() - timeBeginPeriodRetValue = osRelax(false) - - ncpu = getproccount() -@@ -844,9 +886,20 @@ - var thandle uintptr - stdcall7(_DuplicateHandle, currentProcess, currentThread, currentProcess, uintptr(unsafe.Pointer(&thandle)), 0, 0, _DUPLICATE_SAME_ACCESS) - -+ // Configure usleep timer, if possible. -+ var timer uintptr -+ if haveHighResTimer { -+ timer = createHighResTimer() -+ if timer == 0 { -+ print("runtime: CreateWaitableTimerEx failed; errno=", getlasterror(), "\n") -+ throw("CreateWaitableTimerEx when creating timer failed") -+ } -+ } -+ - mp := getg().m - lock(&mp.threadLock) - mp.thread = thandle -+ mp.highResTimer = timer - unlock(&mp.threadLock) - - // Query the true stack base from the OS. Currently we're -@@ -884,6 +937,10 @@ - lock(&mp.threadLock) - stdcall1(_CloseHandle, mp.thread) - mp.thread = 0 -+ if mp.highResTimer != 0 { -+ stdcall1(_CloseHandle, mp.highResTimer) -+ mp.highResTimer = 0 -+ } - unlock(&mp.threadLock) - } - -@@ -979,6 +1036,7 @@ - // in sys_windows_386.s and sys_windows_amd64.s - func onosstack(fn unsafe.Pointer, arg uint32) - func usleep2(usec uint32) -+func usleep2HighRes(usec uint32) - func switchtothread() - - var usleep2Addr unsafe.Pointer -diff --git a/src/runtime/sys_windows_386.s b/src/runtime/sys_windows_386.s -index 9e1f409..4ac1527 100644 ---- a/src/runtime/sys_windows_386.s -+++ b/src/runtime/sys_windows_386.s -@@ -428,6 +428,42 @@ - MOVL BP, SP - RET - -+// Runs on OS stack. duration (in 100ns units) is in BX. -+TEXT runtime·usleep2HighRes(SB),NOSPLIT,$36 -+ // Want negative 100ns units. -+ NEGL BX -+ MOVL $-1, hi-4(SP) -+ MOVL BX, lo-8(SP) -+ -+ get_tls(CX) -+ MOVL g(CX), CX -+ MOVL g_m(CX), CX -+ MOVL (m_mOS+mOS_highResTimer)(CX), CX -+ MOVL CX, saved_timer-12(SP) -+ -+ MOVL $0, fResume-16(SP) -+ MOVL $0, lpArgToCompletionRoutine-20(SP) -+ MOVL $0, pfnCompletionRoutine-24(SP) -+ MOVL $0, lPeriod-28(SP) -+ LEAL lo-8(SP), BX -+ MOVL BX, lpDueTime-32(SP) -+ MOVL CX, hTimer-36(SP) -+ MOVL SP, BP -+ MOVL runtime·_SetWaitableTimer(SB), AX -+ CALL AX -+ MOVL BP, SP -+ -+ MOVL $0, ptime-28(SP) -+ MOVL $0, alertable-32(SP) -+ MOVL saved_timer-12(SP), CX -+ MOVL CX, handle-36(SP) -+ MOVL SP, BP -+ MOVL runtime·_NtWaitForSingleObject(SB), AX -+ CALL AX -+ MOVL BP, SP -+ -+ RET -+ - // Runs on OS stack. - TEXT runtime·switchtothread(SB),NOSPLIT,$0 - MOVL SP, BP -diff --git a/src/runtime/sys_windows_amd64.s b/src/runtime/sys_windows_amd64.s -index 6c8eecd..8475425 100644 ---- a/src/runtime/sys_windows_amd64.s -+++ b/src/runtime/sys_windows_amd64.s -@@ -457,6 +457,38 @@ - MOVQ 40(SP), SP - RET - -+// Runs on OS stack. duration (in 100ns units) is in BX. -+TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$72 -+ MOVQ SP, AX -+ ANDQ $~15, SP // alignment as per Windows requirement -+ MOVQ AX, 64(SP) -+ -+ get_tls(CX) -+ MOVQ g(CX), CX -+ MOVQ g_m(CX), CX -+ MOVQ (m_mOS+mOS_highResTimer)(CX), CX // hTimer -+ MOVQ CX, 48(SP) // save hTimer for later -+ // Want negative 100ns units. -+ NEGQ BX -+ LEAQ 56(SP), DX // lpDueTime -+ MOVQ BX, (DX) -+ MOVQ $0, R8 // lPeriod -+ MOVQ $0, R9 // pfnCompletionRoutine -+ MOVQ $0, AX -+ MOVQ AX, 32(SP) // lpArgToCompletionRoutine -+ MOVQ AX, 40(SP) // fResume -+ MOVQ runtime·_SetWaitableTimer(SB), AX -+ CALL AX -+ -+ MOVQ 48(SP), CX // handle -+ MOVQ $0, DX // alertable -+ MOVQ $0, R8 // ptime -+ MOVQ runtime·_NtWaitForSingleObject(SB), AX -+ CALL AX -+ -+ MOVQ 64(SP), SP -+ RET -+ - // Runs on OS stack. - TEXT runtime·switchtothread(SB),NOSPLIT|NOFRAME,$0 - MOVQ SP, AX -diff --git a/src/runtime/sys_windows_arm.s b/src/runtime/sys_windows_arm.s -index 256b5ff..e6c61a4 100644 ---- a/src/runtime/sys_windows_arm.s -+++ b/src/runtime/sys_windows_arm.s -@@ -468,6 +468,24 @@ - MOVW R4, R13 // Restore SP - MOVM.IA.W (R13), [R4, R15] // pop {R4, pc} - -+// Runs on OS stack. Duration (in 100ns units) is in R0. -+// TODO: neeeds to be implemented properly. -+TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$0 -+ MOVM.DB.W [R4, R14], (R13) // push {r4, lr} -+ MOVW R13, R4 // Save SP -+ SUB $8, R13 // R13 = R13 - 8 -+ BIC $0x7, R13 // Align SP for ABI -+ RSB $0, R0, R3 // R3 = -R0 -+ MOVW $0, R1 // R1 = FALSE (alertable) -+ MOVW $-1, R0 // R0 = handle -+ MOVW R13, R2 // R2 = pTime -+ MOVW R3, 0(R2) // time_lo -+ MOVW R0, 4(R2) // time_hi -+ MOVW runtime·_NtWaitForSingleObject(SB), R3 -+ BL (R3) -+ MOVW R4, R13 // Restore SP -+ MOVM.IA.W (R13), [R4, R15] // pop {R4, pc} -+ - // Runs on OS stack. - TEXT runtime·switchtothread(SB),NOSPLIT|NOFRAME,$0 - MOVM.DB.W [R4, R14], (R13) // push {R4, lr} |