cuda-samples/Samples/3_CUDA_Features/memMapIPCDrv/memMapIpc.cpp

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2022-01-13 14:05:24 +08:00
/* Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of NVIDIA CORPORATION nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This sample demonstrates Inter Process Communication
* using cuMemMap APIs and with one process per GPU for computation.
*/
#include <stdio.h>
#include <string.h>
#include <cstring>
#include <iostream>
#include "cuda.h"
#include "helper_multiprocess.h"
// includes, project
#include <helper_functions.h>
#include "helper_cuda_drvapi.h"
// includes, CUDA
#include <builtin_types.h>
using namespace std;
// For direct NVLINK and PCI-E peers, at max 8 simultaneous peers are allowed
// For NVSWITCH connected peers like DGX-2, simultaneous peers are not limited
// in the same way.
#define MAX_DEVICES (32)
#define PROCESSES_PER_DEVICE 1
#define DATA_BUF_SIZE 4ULL * 1024ULL * 1024ULL
static const char ipcName[] = "memmap_ipc_pipe";
static const char shmName[] = "memmap_ipc_shm";
typedef struct shmStruct_st {
size_t nprocesses;
int barrier;
int sense;
} shmStruct;
bool findModulePath(const char *, string &, char **, string &);
// define input ptx file for different platforms
#if defined(_WIN64) || defined(__LP64__)
#define PTX_FILE "memMapIpc_kernel64.ptx"
#else
#define PTX_FILE "memMapIpc_kernel32.ptx"
#endif
// `ipcHandleTypeFlag` specifies the platform specific handle type this sample
// uses for importing and exporting memory allocation. On Linux this sample
// specifies the type as CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR meaning that
// file descriptors will be used. On Windows this sample specifies the type as
// CU_MEM_HANDLE_TYPE_WIN32 meaning that NT HANDLEs will be used. The
// ipcHandleTypeFlag variable is a convenience variable and is passed by value
// to individual requests.
#if defined(__linux__)
CUmemAllocationHandleType ipcHandleTypeFlag =
CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR;
#else
CUmemAllocationHandleType ipcHandleTypeFlag = CU_MEM_HANDLE_TYPE_WIN32;
#endif
#if defined(__linux__)
#define cpu_atomic_add32(a, x) __sync_add_and_fetch(a, x)
#elif defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
#define cpu_atomic_add32(a, x) InterlockedAdd((volatile LONG *)a, x)
#else
#error Unsupported system
#endif
CUmodule cuModule;
CUfunction _memMapIpc_kernel;
static void barrierWait(volatile int *barrier, volatile int *sense,
unsigned int n) {
int count;
// Check-in
count = cpu_atomic_add32(barrier, 1);
if (count == n) { // Last one in
*sense = 1;
}
while (!*sense)
;
// Check-out
count = cpu_atomic_add32(barrier, -1);
if (count == 0) { // Last one out
*sense = 0;
}
while (*sense)
;
}
// Windows-specific LPSECURITYATTRIBUTES
void getDefaultSecurityDescriptor(CUmemAllocationProp *prop) {
#if defined(__linux__)
return;
#elif defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
static const char sddl[] = "D:P(OA;;GARCSDWDWOCCDCLCSWLODTWPRPCRFA;;;WD)";
static OBJECT_ATTRIBUTES objAttributes;
static bool objAttributesConfigured = false;
if (!objAttributesConfigured) {
PSECURITY_DESCRIPTOR secDesc;
BOOL result = ConvertStringSecurityDescriptorToSecurityDescriptorA(
sddl, SDDL_REVISION_1, &secDesc, NULL);
if (result == 0) {
printf("IPC failure: getDefaultSecurityDescriptor Failed! (%d)\n",
GetLastError());
}
InitializeObjectAttributes(&objAttributes, NULL, 0, NULL, secDesc);
objAttributesConfigured = true;
}
prop->win32HandleMetaData = &objAttributes;
return;
#endif
}
static void memMapAllocateAndExportMemory(
unsigned char backingDevice, size_t allocSize,
std::vector<CUmemGenericAllocationHandle> &allocationHandles,
std::vector<ShareableHandle> &shareableHandles) {
// This property structure describes the physical location where the memory
// will be allocated via cuMemCreate along with additional properties.
CUmemAllocationProp prop = {};
// The allocations will be device pinned memory backed on backingDevice and
// exportable with the specified handle type.
prop.type = CU_MEM_ALLOCATION_TYPE_PINNED;
prop.location.type = CU_MEM_LOCATION_TYPE_DEVICE;
// Back all allocations on backingDevice.
prop.location.id = (int)backingDevice;
// Passing a requestedHandleTypes indicates intention to export this
// allocation to a platform-specific handle. This sample requests a file
// descriptor on Linux and NT Handle on Windows.
prop.requestedHandleTypes = ipcHandleTypeFlag;
// Get the minimum granularity supported for allocation with cuMemCreate()
size_t granularity = 0;
checkCudaErrors(cuMemGetAllocationGranularity(
&granularity, &prop, CU_MEM_ALLOC_GRANULARITY_MINIMUM));
if (allocSize % granularity) {
printf(
"Allocation size is not a multiple of minimum supported granularity "
"for this device. Exiting...\n");
exit(EXIT_FAILURE);
}
// Windows-specific LPSECURITYATTRIBUTES is required when
// CU_MEM_HANDLE_TYPE_WIN32 is used. The security attribute defines the scope
// of which exported allocations may be tranferred to other processes. For all
// other handle types, pass NULL.
getDefaultSecurityDescriptor(&prop);
for (int i = 0; i < allocationHandles.size(); i++) {
// Create the allocation as a pinned allocation on device specified in
// prop.location.id
checkCudaErrors(cuMemCreate(&allocationHandles[i], allocSize, &prop, 0));
// Export the allocation to a platform-specific handle. The type of handle
// requested here must match the requestedHandleTypes field in the prop
// structure passed to cuMemCreate.
checkCudaErrors(cuMemExportToShareableHandle((void *)&shareableHandles[i],
allocationHandles[i],
ipcHandleTypeFlag, 0));
}
}
static void memMapImportAndMapMemory(
CUdeviceptr d_ptr, size_t mapSize,
std::vector<ShareableHandle> &shareableHandles, int mapDevice) {
std::vector<CUmemGenericAllocationHandle> allocationHandles;
allocationHandles.resize(shareableHandles.size());
// The accessDescriptor will describe the mapping requirement for the
// mapDevice passed as argument
CUmemAccessDesc accessDescriptor;
// Specify location for mapping the imported allocations.
accessDescriptor.location.type = CU_MEM_LOCATION_TYPE_DEVICE;
accessDescriptor.location.id = mapDevice;
// Specify both read and write accesses.
accessDescriptor.flags = CU_MEM_ACCESS_FLAGS_PROT_READWRITE;
for (int i = 0; i < shareableHandles.size(); i++) {
// Import the memory allocation back into a CUDA handle from the platform
// specific handle.
checkCudaErrors(cuMemImportFromShareableHandle(
&allocationHandles[i], (void *)(uintptr_t)shareableHandles[i],
ipcHandleTypeFlag));
// Assign the chunk to the appropriate VA range and release the handle.
// After mapping the memory, it can be referenced by virtual address.
checkCudaErrors(
cuMemMap(d_ptr + (i * mapSize), mapSize, 0, allocationHandles[i], 0));
// Since we do not need to make any other mappings of this memory or export
// it, we no longer need and can release the allocationHandle. The
// allocation will be kept live until it is unmapped.
checkCudaErrors(cuMemRelease(allocationHandles[i]));
}
// Retain peer access and map all chunks to mapDevice
checkCudaErrors(cuMemSetAccess(d_ptr, shareableHandles.size() * mapSize,
&accessDescriptor, 1));
}
static void memMapUnmapAndFreeMemory(CUdeviceptr dptr, size_t size) {
CUresult status = CUDA_SUCCESS;
// Unmap the mapped virtual memory region
// Since the handles to the mapped backing stores have already been released
// by cuMemRelease, and these are the only/last mappings referencing them,
// The backing stores will be freed.
// Since the memory has been unmapped after this call, accessing the specified
// va range will result in a fault (unitll it is remapped).
checkCudaErrors(cuMemUnmap(dptr, size));
// Free the virtual address region. This allows the virtual address region
// to be reused by future cuMemAddressReserve calls. This also allows the
// virtual address region to be used by other allocation made through
// opperating system calls like malloc & mmap.
checkCudaErrors(cuMemAddressFree(dptr, size));
}
static void memMapGetDeviceFunction(char **argv) {
// first search for the module path before we load the results
string module_path, ptx_source;
if (!findModulePath(PTX_FILE, module_path, argv, ptx_source)) {
if (!findModulePath("memMapIpc_kernel.cubin", module_path, argv,
ptx_source)) {
printf(
"> findModulePath could not find <simpleMemMapIpc> ptx or cubin\n");
exit(EXIT_FAILURE);
}
} else {
printf("> initCUDA loading module: <%s>\n", module_path.c_str());
}
// Create module from binary file (PTX or CUBIN)
if (module_path.rfind("ptx") != string::npos) {
// in this branch we use compilation with parameters
const unsigned int jitNumOptions = 3;
CUjit_option *jitOptions = new CUjit_option[jitNumOptions];
void **jitOptVals = new void *[jitNumOptions];
// set up size of compilation log buffer
jitOptions[0] = CU_JIT_INFO_LOG_BUFFER_SIZE_BYTES;
int jitLogBufferSize = 1024;
jitOptVals[0] = (void *)(size_t)jitLogBufferSize;
// set up pointer to the compilation log buffer
jitOptions[1] = CU_JIT_INFO_LOG_BUFFER;
char *jitLogBuffer = new char[jitLogBufferSize];
jitOptVals[1] = jitLogBuffer;
// set up pointer to set the Maximum # of registers for a particular kernel
jitOptions[2] = CU_JIT_MAX_REGISTERS;
int jitRegCount = 32;
jitOptVals[2] = (void *)(size_t)jitRegCount;
checkCudaErrors(cuModuleLoadDataEx(&cuModule, ptx_source.c_str(),
jitNumOptions, jitOptions,
(void **)jitOptVals));
printf("> PTX JIT log:\n%s\n", jitLogBuffer);
} else {
checkCudaErrors(cuModuleLoad(&cuModule, module_path.c_str()));
}
// Get function handle from module
checkCudaErrors(
cuModuleGetFunction(&_memMapIpc_kernel, cuModule, "memMapIpc_kernel"));
}
static void childProcess(int devId, int id, char **argv) {
volatile shmStruct *shm = NULL;
sharedMemoryInfo info;
ipcHandle *ipcChildHandle = NULL;
int blocks = 0;
int threads = 128;
checkIpcErrors(ipcOpenSocket(ipcChildHandle));
if (sharedMemoryOpen(shmName, sizeof(shmStruct), &info) != 0) {
printf("Failed to create shared memory slab\n");
exit(EXIT_FAILURE);
}
shm = (volatile shmStruct *)info.addr;
int procCount = (int)shm->nprocesses;
barrierWait(&shm->barrier, &shm->sense, (unsigned int)(procCount + 1));
// Receive all allocation handles shared by Parent.
std::vector<ShareableHandle> shHandle(procCount);
checkIpcErrors(ipcRecvShareableHandles(ipcChildHandle, shHandle));
CUcontext ctx;
CUdevice device;
CUstream stream;
int multiProcessorCount;
checkCudaErrors(cuDeviceGet(&device, devId));
checkCudaErrors(cuCtxCreate(&ctx, 0, device));
checkCudaErrors(cuStreamCreate(&stream, CU_STREAM_NON_BLOCKING));
// Obtain kernel function for the sample
memMapGetDeviceFunction(argv);
checkCudaErrors(cuOccupancyMaxActiveBlocksPerMultiprocessor(
&blocks, _memMapIpc_kernel, threads, 0));
checkCudaErrors(cuDeviceGetAttribute(
&multiProcessorCount, CU_DEVICE_ATTRIBUTE_MULTIPROCESSOR_COUNT, device));
blocks *= multiProcessorCount;
CUdeviceptr d_ptr = 0ULL;
// Reserve the required contiguous VA space for the allocations
checkCudaErrors(cuMemAddressReserve(&d_ptr, procCount * DATA_BUF_SIZE,
DATA_BUF_SIZE, 0, 0));
// Import the memory allocations shared by the parent with us and map them in
// our address space.
memMapImportAndMapMemory(d_ptr, DATA_BUF_SIZE, shHandle, devId);
// Since we have imported allocations shared by the parent with us, we can
// close all the ShareableHandles.
for (int i = 0; i < procCount; i++) {
checkIpcErrors(ipcCloseShareableHandle(shHandle[i]));
}
checkIpcErrors(ipcCloseSocket(ipcChildHandle));
for (int i = 0; i < procCount; i++) {
size_t bufferId = (i + id) % procCount;
// Build arguments to be passed to cuda kernel.
CUdeviceptr ptr = d_ptr + (bufferId * DATA_BUF_SIZE);
int size = DATA_BUF_SIZE;
char val = (char)id;
void *args[] = {&ptr, &size, &val};
// Push a simple kernel on th buffer.
checkCudaErrors(cuLaunchKernel(_memMapIpc_kernel, blocks, 1, 1, threads, 1,
1, 0, stream, args, 0));
checkCudaErrors(cuStreamSynchronize(stream));
// Wait for all my sibling processes to push this stage of their work
// before proceeding to the next. This makes the data in the buffer
// deterministic.
barrierWait(&shm->barrier, &shm->sense, (unsigned int)procCount);
if (id == 0) {
printf("Step %lld done\n", (unsigned long long)i);
}
}
printf("Process %d: verifying...\n", id);
// Copy the data onto host and verify value if it matches expected value or
// not.
std::vector<char> verification_buffer(DATA_BUF_SIZE);
checkCudaErrors(cuMemcpyDtoHAsync(&verification_buffer[0],
d_ptr + (id * DATA_BUF_SIZE), DATA_BUF_SIZE,
stream));
checkCudaErrors(cuStreamSynchronize(stream));
// The contents should have the id of the sibling just after me
char compareId = (char)((id + 1) % procCount);
for (unsigned long long j = 0; j < DATA_BUF_SIZE; j++) {
if (verification_buffer[j] != compareId) {
printf("Process %d: Verification mismatch at %lld: %d != %d\n", id, j,
(int)verification_buffer[j], (int)compareId);
break;
}
}
// Clean up!
checkCudaErrors(cuStreamDestroy(stream));
checkCudaErrors(cuCtxDestroy(ctx));
// Unmap the allocations from our address space. Unmapping will also free the
// handle as we have already released the imported handle with the call to
// cuMemRelease. Finally, free up the Virtual Address space we reserved with
// cuMemAddressReserve.
memMapUnmapAndFreeMemory(d_ptr, procCount * DATA_BUF_SIZE);
exit(EXIT_SUCCESS);
}
static void parentProcess(char *app) {
int devCount, i, nprocesses = 0;
volatile shmStruct *shm = NULL;
sharedMemoryInfo info;
std::vector<Process> processes;
checkCudaErrors(cuDeviceGetCount(&devCount));
std::vector<CUdevice> devices(devCount);
if (sharedMemoryCreate(shmName, sizeof(*shm), &info) != 0) {
printf("Failed to create shared memory slab\n");
exit(EXIT_FAILURE);
}
shm = (volatile shmStruct *)info.addr;
memset((void *)shm, 0, sizeof(*shm));
for (i = 0; i < devCount; i++) {
checkCudaErrors(cuDeviceGet(&devices[i], i));
}
std::vector<CUcontext> ctxs;
std::vector<unsigned char> selectedDevices;
// Pick all the devices that can access each other's memory for this test
// Keep in mind that CUDA has minimal support for fork() without a
// corresponding exec() in the child process, but in this case our
// spawnProcess will always exec, so no need to worry.
for (i = 0; i < devCount; i++) {
bool allPeers = true;
int deviceComputeMode;
int deviceSupportsIpcHandle;
int attributeVal = 0;
checkCudaErrors(cuDeviceGet(&devices[i], i));
checkCudaErrors(cuDeviceGetAttribute(
&deviceComputeMode, CU_DEVICE_ATTRIBUTE_COMPUTE_MODE, devices[i]));
checkCudaErrors(cuDeviceGetAttribute(
&attributeVal, CU_DEVICE_ATTRIBUTE_VIRTUAL_ADDRESS_MANAGEMENT_SUPPORTED,
devices[i]));
#if defined(__linux__)
checkCudaErrors(cuDeviceGetAttribute(
&deviceSupportsIpcHandle,
CU_DEVICE_ATTRIBUTE_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR_SUPPORTED,
devices[i]));
#else
checkCudaErrors(cuDeviceGetAttribute(
&deviceSupportsIpcHandle,
CU_DEVICE_ATTRIBUTE_HANDLE_TYPE_WIN32_HANDLE_SUPPORTED, devices[i]));
#endif
// Check that the selected device supports virtual address management
if (attributeVal == 0) {
printf("Device %d doesn't support VIRTUAL ADDRESS MANAGEMENT.\n",
devices[i]);
continue;
}
// This sample requires two processes accessing each device, so we need
// to ensure exclusive or prohibited mode is not set
if (deviceComputeMode != CU_COMPUTEMODE_DEFAULT) {
printf("Device %d is in an unsupported compute mode for this sample\n",
i);
continue;
}
if (!deviceSupportsIpcHandle) {
printf(
"Device %d does not support requested handle type for IPC, "
"skipping...\n",
i);
continue;
}
for (int j = 0; j < nprocesses; j++) {
int canAccessPeerIJ, canAccessPeerJI;
checkCudaErrors(
cuDeviceCanAccessPeer(&canAccessPeerJI, devices[j], devices[i]));
checkCudaErrors(
cuDeviceCanAccessPeer(&canAccessPeerIJ, devices[i], devices[j]));
if (!canAccessPeerIJ || !canAccessPeerJI) {
allPeers = false;
break;
}
}
if (allPeers) {
CUcontext ctx;
checkCudaErrors(cuCtxCreate(&ctx, 0, devices[i]));
ctxs.push_back(ctx);
// Enable peers here. This isn't necessary for IPC, but it will
// setup the peers for the device. For systems that only allow 8
// peers per GPU at a time, this acts to remove devices from CanAccessPeer
for (int j = 0; j < nprocesses; j++) {
checkCudaErrors(cuCtxSetCurrent(ctxs[i]));
checkCudaErrors(cuCtxEnablePeerAccess(ctxs[j], 0));
checkCudaErrors(cuCtxSetCurrent(ctxs[j]));
checkCudaErrors(cuCtxEnablePeerAccess(ctxs[i], 0));
}
selectedDevices.push_back(i);
nprocesses++;
if (nprocesses >= MAX_DEVICES) {
break;
}
} else {
printf(
"Device %d is not peer capable with some other selected peers, "
"skipping\n",
i);
}
}
for (int i = 0; i < ctxs.size(); ++i) {
checkCudaErrors(cuCtxDestroy(ctxs[i]));
};
if (nprocesses == 0) {
printf("No CUDA devices support IPC\n");
exit(EXIT_WAIVED);
}
shm->nprocesses = nprocesses;
unsigned char firstSelectedDevice = selectedDevices[0];
std::vector<ShareableHandle> shHandles(nprocesses);
std::vector<CUmemGenericAllocationHandle> allocationHandles(nprocesses);
// Allocate `nprocesses` number of memory chunks and obtain a shareable handle
// for each allocation. Share all memory allocations with all children.
memMapAllocateAndExportMemory(firstSelectedDevice, DATA_BUF_SIZE,
allocationHandles, shHandles);
// Launch the child processes!
for (i = 0; i < nprocesses; i++) {
char devIdx[10];
char procIdx[10];
char *const args[] = {app, devIdx, procIdx, NULL};
Process process;
SPRINTF(devIdx, "%d", selectedDevices[i]);
SPRINTF(procIdx, "%d", i);
if (spawnProcess(&process, app, args)) {
printf("Failed to create process\n");
exit(EXIT_FAILURE);
}
processes.push_back(process);
}
barrierWait(&shm->barrier, &shm->sense, (unsigned int)(nprocesses + 1));
ipcHandle *ipcParentHandle = NULL;
checkIpcErrors(ipcCreateSocket(ipcParentHandle, ipcName, processes));
checkIpcErrors(
ipcSendShareableHandles(ipcParentHandle, shHandles, processes));
// Close the shareable handles as they are not needed anymore.
for (int i = 0; i < nprocesses; i++) {
checkIpcErrors(ipcCloseShareableHandle(shHandles[i]));
}
// And wait for them to finish
for (i = 0; i < processes.size(); i++) {
if (waitProcess(&processes[i]) != EXIT_SUCCESS) {
printf("Process %d failed!\n", i);
exit(EXIT_FAILURE);
}
}
for (i = 0; i < nprocesses; i++) {
checkCudaErrors(cuMemRelease(allocationHandles[i]));
}
checkIpcErrors(ipcCloseSocket(ipcParentHandle));
sharedMemoryClose(&info);
}
// Host code
int main(int argc, char **argv) {
// Initialize
checkCudaErrors(cuInit(0));
if (argc == 1) {
parentProcess(argv[0]);
} else {
childProcess(atoi(argv[1]), atoi(argv[2]), argv);
}
return EXIT_SUCCESS;
}
bool inline findModulePath(const char *module_file, string &module_path,
char **argv, string &ptx_source) {
char *actual_path = sdkFindFilePath(module_file, argv[0]);
if (actual_path) {
module_path = actual_path;
} else {
printf("> findModulePath file not found: <%s> \n", module_file);
return false;
}
if (module_path.empty()) {
printf("> findModulePath could not find file: <%s> \n", module_file);
return false;
} else {
printf("> findModulePath found file at <%s>\n", module_path.c_str());
if (module_path.rfind(".ptx") != string::npos) {
FILE *fp = fopen(module_path.c_str(), "rb");
fseek(fp, 0, SEEK_END);
int file_size = ftell(fp);
char *buf = new char[file_size + 1];
fseek(fp, 0, SEEK_SET);
fread(buf, sizeof(char), file_size, fp);
fclose(fp);
buf[file_size] = '\0';
ptx_source = buf;
delete[] buf;
}
return true;
}
}