cavis/libnd4j/include/execution/cuda/AffinityManager.cu

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/*******************************************************************************
* Copyright (c) 2015-2018 Skymind, Inc.
*
* This program and the accompanying materials are made available under the
* terms of the Apache License, Version 2.0 which is available at
* https://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
* SPDX-License-Identifier: Apache-2.0
******************************************************************************/
//
// @author raver119@gmail.com
//
#include <logger.h>
#include <execution/AffinityManager.h>
#include <exceptions/cuda_exception.h>
#include <LaunchContext.h>
thread_local int globalThreadToDevice = -1;
namespace nd4j {
std::mutex AffinityManager::_currentMutex;
std::mutex AffinityManager::_numberMutex;
int AffinityManager::_numberOfDevices = -1;
int AffinityManager::currentDeviceId() {
// if there's no affinity set - set it now
if (globalThreadToDevice < 0) {
// this block must be thread-local
_currentMutex.lock();
globalThreadToDevice = _lastDevice++;
// we need to check if we've got deviceId >= number of actual devices, and reset to zero otherwise
if (globalThreadToDevice >= numberOfDevices()) {
globalThreadToDevice = 0;
_lastDevice = numberOfDevices() > 1 ? 1 : 0;
}
_currentMutex.unlock();
setCurrentNativeDevice(globalThreadToDevice);
}
// if we already know affinity - just return it
if (globalThreadToDevice >= 0)
return globalThreadToDevice;
int dev = 0;
auto res = cudaGetDevice(&dev);
if (res != 0)
throw cuda_exception::build("cudaGetDevice failed", res);
return dev;
}
int AffinityManager::currentNativeDeviceId() {
int dev = 0;
auto res = cudaGetDevice(&dev);
if (res != 0)
throw cuda_exception::build("cudaGetDevice failed", res);
return dev;
}
int AffinityManager::numberOfDevices() {
_numberMutex.lock();
// we want to cache number of devices
if (_numberOfDevices <= 0) {
int dev = 0;
auto res = cudaGetDeviceCount(&dev);
if (res != 0)
throw cuda_exception::build("cudaGetDeviceCount failed", res);
_numberOfDevices = dev;
}
_numberMutex.unlock();
return _numberOfDevices;
}
void AffinityManager::setCurrentNativeDevice(int deviceId) {
auto res = cudaSetDevice(deviceId);
if (res != 0)
throw cuda_exception::build("setCurrentDevice failed", res);
}
void AffinityManager::setCurrentDevice(int deviceId) {
auto previousDeviceId = globalThreadToDevice;
if (previousDeviceId >= 0 && LaunchContext::isInitialized()) {
auto res = cudaStreamSynchronize(*LaunchContext::defaultContext()->getCudaStream());
if (res != 0)
throw cuda_exception::build("setCurrentDevice -> sync failed", res);
res = cudaStreamSynchronize(*LaunchContext::defaultContext()->getCudaSpecialStream());
if (res != 0)
throw cuda_exception::build("setCurrentDevice -> specialSync failed", res);
if (deviceId != previousDeviceId) {
// discard existing stuff
nd4j_printf("AffinityManager::setCurrentDevice() was invoked, releasing buffers\n", "");
LaunchContext::releaseBuffers();
}
}
if (deviceId != previousDeviceId) {
auto res = cudaSetDevice(deviceId);
if (res != 0)
throw cuda_exception::build("cudaSetDevice failed", res);
}
// update thread-device affinity
globalThreadToDevice = deviceId;
}
std::atomic<int> AffinityManager::_lastDevice;// = std::atomic<int>(initialV);
}