remove CPU from default candidate list while GPUs more than 2 (#11753)

src/plugins/auto/auto_schedule.cpp

@@ -123,6 +123,36 @@ void AutoSchedule::init(const ScheduleContext::Ptr& sContext) {
         std::list<DeviceInformation> validDevices =
             _autoSContext->_plugin->GetValidDevice(_autoSContext->_devicePriorities, _loadContext[ACTUALDEVICE].networkPrecision);
 
+        // check if device priority is enabled
+        bool enableDevicePriority =
+            std::find_if(std::begin(validDevices), std::end(validDevices), [](DeviceInformation& di) {
+                return di.devicePriority > 0;
+            }) != std::end(validDevices);
+
+        // for the case of -d "AUTO" or "AUTO: -xxx"
+        if (!enableDevicePriority) {
+            std::list<DeviceInformation>::iterator itCPUDevice;
+            int GPUNums = 0, CPUNums = 0;
+            for (auto it = validDevices.begin(); it != validDevices.end(); it++) {
+                if (it->deviceName.find("GPU") != std::string::npos) {
+                    GPUNums++;
+                }
+
+                if (it->deviceName.find("CPU") == 0) {
+                    CPUNums++;
+                    itCPUDevice = it;
+                }
+            }
+
+            // remove CPU from default candidate list for Cumulative Throughput mode
+            if (GPUNums >= 2 && CPUNums > 0) {
+                validDevices.erase(itCPUDevice);
+                LOG_INFO("[AUTOPLUGIN]:GPUNums:%d, remove CPU from default candidate list for "
+                         "CUMULATIVE_THROUGHPUT",
+                         GPUNums);
+            }
+        }
+
         std::string deviceName = "MULTI:";
         for (auto& device : validDevices) {
             deviceName += device.deviceName;