set grad = 0 after each update of a model

source/train/TTrain.cpp

@@ -77,12 +77,12 @@ void TestTrain()
 
     XConfig config;
     //config.Add("dev", -1);
-    config.Add("lrate", 0.001F);
+    config.Add("lrate", 0.1F);
     config.Add("nstep", 100000);
     config.Add("nepoch", 5);
-    config.Add("jobdev0", 0);
-    config.Add("jobdev1", -1);
-    config.Add("jobdev2", -1);
+    config.Add("jobdev0", -1);
+    config.Add("jobdev1", 0);
+    //config.Add("jobdev2", -1);
     //config.Add("jobdev3", -1);
     //config.Add("jobdev4", -1);
 

source/train/XLeader.cpp

@@ -136,11 +136,34 @@ void XLeader::InitForRun()
     }
 }
 
+/* set grad = 0 */
+void XLeader::ResetParamGrad()
+{
+    for (int i = 0; i < serverModel.paramNum; i++) {
+        XTensor* param = serverModel.params[i].param;
+        if (param->grad != NULL) {
+            param->grad->SetZeroAll();
+        }
+    }
+
+    for (int j = 0; j < jworkers.count; j++) {
+        XWorkerJob * worker = (XWorkerJob*)jworkers[j];
+        XModel * model = worker->GetModel();
+        for (int i = 0; i < model->paramNum; i++) {
+            XTensor* param = model->params[i].param;
+            if (param->grad != NULL) {
+                param->grad->SetZeroAll();
+            }
+        }
+    }
+}
+
 /*
 wait for finished states (i.e., all workers finish their jobs)
 >> activeJobWorkers - indicates whether each job worker is active
+>> isToUpdate - indicates whether the model is updated
 */
-void XLeader::WaitForFinishing(const int* activeJobWorkers)
+void XLeader::WaitForFinishing(const int* activeJobWorkers, const int isToUpdate)
 {
     int activeCount = 0;
     for (int i = 0; i < jworkers.count; i++) {
@@ -151,7 +174,7 @@ void XLeader::WaitForFinishing(const int* activeJobWorkers)
         }
     }
 
-    if (activeCount > 0) {
+    if (activeCount > 0 && isToUpdate) {
         for (int i = 0; i < cworkers.count; i++) {
             XWorker* worker = (XWorker*)cworkers[i];
             worker->DequeueFinishedJob();
@@ -319,6 +342,7 @@ bool XLeader::Run(XConfig * config, DataDistributeBase * dataDistributor,
     CheckNTErrors(bworkers.count > 0, "No bworkers!");
 
     bool isDataOK = true;
+    bool isToUpdate = (optimizer != NULL);
     int activeJobCount = 0;
     int* active = new int[jworkers.count];
     
@@ -360,7 +384,7 @@ bool XLeader::Run(XConfig * config, DataDistributeBase * dataDistributor,
         }
     }
 
-    if (activeJobCount > 0) {
+    if (activeJobCount > 0 && isToUpdate) {
         /* workers */
         XWorkerCollect * collecter = (XWorkerCollect*)cworkers.GetItem(0);
         XWorkerUpdate * updater = (XWorkerUpdate*)uworkers.GetItem(0);
@@ -384,28 +408,18 @@ bool XLeader::Run(XConfig * config, DataDistributeBase * dataDistributor,
             }
         }
 
+        /* jobs in queue 2: collect the (gradient) data and other stuff. This
+           is a reduce process. The collector will add a job in queue 3
+           to update the model. The updater will  add a job job in queue 4 to 
+           broadcast the lastest parameters to workers. NOTE that we would update 
+           a worker to the laster model parameters, even if it is not involved 
+           in this run. */
         collecter->AddJobUpdateAll(&members, &membersAll, &serverModel, 
-                                   optimizer, updater, broadcaster);
-        //collecter->AddJobCollectOther(&memberRecords, &serverRecord);
+                                    optimizer, updater, broadcaster);
         collecter->AddJobEnqueueFinished();
-        
-        /* jobs in queue 2: collect the (gradient) data and other stuff. This
-           is a reduce process. */
-        //collecter->AddJobCollect(&members, &serverModel);
-        //collecter->AddJobCollectOther(&memberRecords, &serverRecord);
-
-        /* job in queue 3: update the model */
-        //updater->AddJobUpdate(&serverModel, optimizer);
-
-        /* job in queue 4: broadcast the lastest parameters to workers. NOTE that
-           we would update a worker to the laster model parameters, even if it is
-           not involved in this run. */
-        //broadcaster->AddJobBroadcast(&serverModel, &membersAll);
-
-        //WaitForFinishing();
     }
 
-    WaitForFinishing(active);
+    WaitForFinishing(active, isToUpdate);
 
     for (int i = 0; i < jworkers.count; i++) {
         XWorkerJob * worker = (XWorkerJob*)jworkers[i];

source/train/XLeader.h

@@ -112,8 +112,11 @@ public:
     /* initialize the models for running them */
     void InitForRun();
 
+    /* set grad = 0 */
+    void ResetParamGrad();
+
     /* wait for finished states (i.e., all workers finish their jobs) */
-    void WaitForFinishing(const int * activeJobWorkers);
+    void WaitForFinishing(const int * activeJobWorkers, const int isToUpdate);
 
     /* get loss */
     float GetLoss();

source/train/XTrainer.cpp

@@ -96,7 +96,11 @@ void XTrainer::Run(XConfig * config, DataDistributeBase * dataDistributor,
 
     int epoch = 0;
     int step = 0;
+    int stepAll = 0;
     int jobNum = 0;
+    int accumulation = config->GetInt("accumulation", 1);
+
+    CheckNTErrors(accumulation >= 1, "accumulation must be larger than 0!");
 
     int * ids = new int[MAX_DEVICE_NUM_TRAINING];
     GetDevIDs(config, ids, jobNum, MAX_DEVICE_NUM_TRAINING);
@@ -126,18 +130,26 @@ void XTrainer::Run(XConfig * config, DataDistributeBase * dataDistributor,
         dataDistributor->Start();
 
         while (ok) {
+            if (++stepAll % accumulation == 0) {
 
-            /* one step of udpate */
-            ok = leader.Run(config, dataDistributor, model, optimizer);
+                /* one step of udpate */
+                ok = leader.Run(config, dataDistributor, model, optimizer);
 
-            float loss = leader.GetLoss() / leader.GetSampleNum();
+                float loss = leader.GetLoss() / leader.GetSampleNum();
 
-            if ((step + 1) % 100 == 0)
-                XPRINT5(1, stderr, "[INFO] elapsed=%.1fs epoch:%d step:%d sample:%d loss:%f\n",
+                if ((step + 1) % 100 == 0)
+                    XPRINT5(1, stderr, "[INFO] elapsed=%.1fs epoch:%d step:%d sample:%d loss:%f\n",
                         GetClockSec() - startT, epoch + 1, step + 1, leader.GetSampleNum(), loss);
 
-            if (++step >= optimizer->nstep)
-                break;
+                leader.ResetParamGrad();
+
+                if (++step >= optimizer->nstep)
+                    break;
+            }
+            else {
+                /* one step with no udpate */
+                ok = leader.Run(config, dataDistributor, model, NULL);
+            }
         }
 
         dataDistributor->End();
@@ -169,6 +181,8 @@ void XTrainer::ShowSettings(XConfig* config)
         }
     }
 
+    XPRINT2(1, stderr, "%25s = %d\n", "accumulation", config->GetInt("accumulation", 1));
+
     delete[] ids;
 }
 

source/train/XWorkerCollect.cpp

@@ -127,7 +127,6 @@ void XWorkerCollect::UpdateDataAll(XList * memberActive, XList * memberAll, XMod
                             if (updater != NULL) {
                                 updater->AddJobUpdateSingle(server, memberAll, j, optimizer, broadcaster);
                                 updater->AddJobEnqueueFinished();
-
                             }
                         }
                         else if (finishedCount[j] > memberActive->count) {
@@ -195,8 +194,18 @@ void XWorkerCollect::CollectP2P(XTensor * source, XTensor * target)
     CheckNTErrors(IsSameShaped(*source, *target), "The two tensors should be of the same shape!");
 
     /* target += source */
-    if(source != target)
-        _Sum(source, target, source);
+    if (source != target) {
+        XTensor * sourceOnSite = source;
+        if (source->devID != target->devID) {
+            sourceOnSite = new XTensor(target);
+            _CopyValues(source, sourceOnSite);
+        }
+
+        _Sum(target, sourceOnSite, target);
+
+        if (sourceOnSite != source)
+            delete sourceOnSite;
+    }
 }
 
 /* 

source/train/XWorkerUpdate.cpp

@@ -142,7 +142,8 @@ void XWorkerUpdate::UpdateSingle(XList * args)
     XOptimizer * optimizer = (XOptimizer*)args->GetItem(3 + memNum + 1);
     XWorkerBroadcast * broadcaster = (XWorkerBroadcast*)args->GetItem(3 + memNum + 2);
 
-    updater->UpdateParameter(server, &members, pid, optimizer, broadcaster);
+    if(updater != NULL)
+        updater->UpdateParameter(server, &members, pid, optimizer, broadcaster);
 }
 
 /* 
@@ -159,7 +160,8 @@ void XWorkerUpdate::Update(XList * args)
     XModel * model = (XModel*)args->GetItem(1);
     XOptimizer * optimizer = (XOptimizer*)args->GetItem(2);
 
-    updater->UpdateModel(model, optimizer, SLEEP_TIME_IN_MODEL_UPDATE);
+    if(updater != NULL)
+        updater->UpdateModel(model, optimizer, SLEEP_TIME_IN_MODEL_UPDATE);
 
     //fprintf(stderr, "update 1\n");
 }