1/* Copyright 2015 The TensorFlow Authors. All Rights Reserved.
2
3Licensed under the Apache License, Version 2.0 (the "License");
4you may not use this file except in compliance with the License.
5You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9Unless required by applicable law or agreed to in writing, software
10distributed under the License is distributed on an "AS IS" BASIS,
11WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12See the License for the specific language governing permissions and
13limitations under the License.
14==============================================================================*/
15
16#include <vector>
17
18// Register a factory that provides CPU devices.
19#include "absl/memory/memory.h"
20#include "tensorflow/core/common_runtime/device_factory.h"
21#include "tensorflow/core/common_runtime/process_state.h"
22#include "tensorflow/core/common_runtime/threadpool_device.h"
23#include "tensorflow/core/framework/allocator.h"
24#include "tensorflow/core/platform/numa.h"
25#include "tensorflow/core/public/session_options.h"
26
27namespace tensorflow {
28
29// TODO(zhifengc/tucker): Figure out the bytes of available RAM.
30class ThreadPoolDeviceFactory : public DeviceFactory {
31 public:
32 Status ListPhysicalDevices(std::vector<string>* devices) override {
33 devices->push_back("/physical_device:CPU:0");
34
35 return OkStatus();
36 }
37
38 Status CreateDevices(const SessionOptions& options, const string& name_prefix,
39 std::vector<std::unique_ptr<Device>>* devices) override {
40 int num_numa_nodes = port::NUMANumNodes();
41 int n = 1;
42 auto iter = options.config.device_count().find("CPU");
43 if (iter != options.config.device_count().end()) {
44 n = iter->second;
45 }
46 for (int i = 0; i < n; i++) {
47 string name = strings::StrCat(name_prefix, "/device:CPU:", i);
48 std::unique_ptr<ThreadPoolDevice> tpd;
49 if (options.config.experimental().use_numa_affinity()) {
50 int numa_node = i % num_numa_nodes;
51 if (numa_node != i) {
52 LOG(INFO) << "Only " << num_numa_nodes
53 << " NUMA nodes visible in system, "
54 << " assigning device " << name << " to NUMA node "
55 << numa_node;
56 }
57 DeviceLocality dev_locality;
58 dev_locality.set_numa_node(numa_node);
59 tpd = std::make_unique<ThreadPoolDevice>(
60 options, name, Bytes(256 << 20), dev_locality,
61 ProcessState::singleton()->GetCPUAllocator(numa_node));
62 } else {
63 tpd = std::make_unique<ThreadPoolDevice>(
64 options, name, Bytes(256 << 20), DeviceLocality(),
65 ProcessState::singleton()->GetCPUAllocator(port::kNUMANoAffinity));
66 }
67 devices->push_back(std::move(tpd));
68 }
69
70 return OkStatus();
71 }
72};
73
74REGISTER_LOCAL_DEVICE_FACTORY("CPU", ThreadPoolDeviceFactory, 60);
75
76} // namespace tensorflow
77