[c10d] Print certain logs only on head rank of each node (#125432)

kwen2501 · pytorchmergebot · commit c921c5cc779b · 2024-05-23T19:16:11.000Z
Recently we added the following warning, which is printed on every rank and makes the log a bit verbose. This PR dedups certain logs that are identical across ranks and prints them only on head rank of each node. Resolves #126275 ========================================= [rank0]:[W502 14:06:55.821964708 ProcessGroupNCCL.cpp:1113] WARNING: process group has NOT been destroyed before it is being destructed. On normal program exit, the application should call destroy_process_group to ensure that any pending NCCL data transfers have finished in this process. In rare cases this process can exit before this point and block the progress of another member of the process group. This constraint has always been present, but this warning has only been added since PyTorch 2.4 [rank1]:[W502 14:06:57.994276972 ProcessGroupNCCL.cpp:1113] WARNING: process group has NOT been destroyed before it is being destructed. On normal program exit, the application should call destroy_process_group to ensure that any pending NCCL data transfers have finished in this process. In rare cases this process can exit before this point and block the progress of another member of the process group. This constraint has always been present, but this warning has only been added since PyTorch 2.4 [rank2]:[W502 14:07:00.353013116 ProcessGroupNCCL.cpp:1113] WARNING: process group has NOT been destroyed before it is being destructed. On normal program exit, the application should call destroy_process_group to ensure that any pending NCCL data transfers have finished in this process. In rare cases this process can exit before this point and block the progress of another member of the process group. This constraint has always been present, but this warning has only been added since PyTorch 2.4 [rank3]:[W502 14:07:02.515511670 ProcessGroupNCCL.cpp:1113] WARNING: process group has NOT been destroyed before it is being destructed. On normal program exit, the application should call destroy_process_group to ensure that any pending NCCL data transfers have finished in this process. In rare cases this process can exit before this point and block the progress of another member of the process group. This constraint has always been present, but this warning has only been added since PyTorch 2.4 Pull Request resolved: #125432 Approved by: https://github.com/wconstab
diff --git a/torch/csrc/distributed/c10d/ProcessGroupNCCL.cpp b/torch/csrc/distributed/c10d/ProcessGroupNCCL.cpp
@@ -398,8 +398,7 @@ at::Device ProcessGroupNCCL::guessDeviceForRank() const {
   if (getBoundDeviceId()) {
     return *getBoundDeviceId();
   } else {
-    auto numGPUs = at::cuda::getNumGPUs();
-    int16_t deviceIdx = static_cast<int16_t>(rank_ % numGPUs);
+    int16_t deviceIdx = static_cast<int16_t>(rank_ % localDeviceCount_);
     return at::Device(at::DeviceType::CUDA, deviceIdx);
   }
 }
@@ -740,6 +739,7 @@ ProcessGroupNCCL::ProcessGroupNCCL(
       at::cuda::getNumGPUs() != 0,
       "ProcessGroupNCCL is only supported with GPUs, no GPUs found!");
   this->setGroupName(options_->group_name);
+  this->localDeviceCount_ = at::cuda::getNumGPUs();
   logPrefix_ = createLogPrefix();
   blockingWait_ = getCvarBool(TORCH_NCCL_BLOCKING_WAIT, false);
   asyncErrorHandling_ = static_cast<ErrorHandlingMode>(
@@ -816,20 +816,23 @@ ProcessGroupNCCL::ProcessGroupNCCL(
   std::string torch_distributed_debug =
       getCvarString({"TORCH_DISTRIBUTED_DEBUG"}, OFF.c_str());
   LOG(INFO) << logPrefix() << "ProcessGroupNCCL initialization options: "
-            << "NCCL version: " << getNcclVersion() << ", size: " << size
-            << ", global rank: " << globalRank()
+            << "size: " << size << ", global rank: " << globalRank()
+            << ", TIMEOUT(ms): " << options_->timeout.count()
+            << ", USE_HIGH_PRIORITY_STREAM: "
+            << options_->is_high_priority_stream
+            << ", SPLIT_FROM: " << options_->split_from
+            << ", SPLIT_COLOR: " << options_->split_color
+            << ", PG Name: " << options_->group_name;
+
+  LOG(INFO) << logPrefix() << "ProcessGroupNCCL environments: "
+            << "NCCL version: " << getNcclVersion()
             << ", TORCH_NCCL_ASYNC_ERROR_HANDLING: " << asyncErrorHandling_
             << ", TORCH_NCCL_DUMP_ON_TIMEOUT: " << dumpOnException_
             << ", TORCH_NCCL_WAIT_TIMEOUT_DUMP_MILSEC: "
             << waitTimeoutDumpInMilSec_
             << ", TORCH_NCCL_DESYNC_DEBUG: " << desyncDebug_
             << ", TORCH_NCCL_ENABLE_TIMING: " << enableTiming_.load()
             << ", TORCH_NCCL_BLOCKING_WAIT: " << blockingWait_
-            << ", TIMEOUT(ms): " << options_->timeout.count()
-            << ", USE_HIGH_PRIORITY_STREAM: "
-            << options_->is_high_priority_stream
-            << ", SPLIT_FROM: " << options_->split_from
-            << ", SPLIT_COLOR: " << options_->split_color
             << ", TORCH_DISTRIBUTED_DEBUG: " << torch_distributed_debug
 #ifdef NCCL_HAS_COMM_REGISTER
             << ", TORCH_NCCL_USE_TENSOR_REGISTER_ALLOCATOR_HOOK: "
@@ -840,8 +843,7 @@ ProcessGroupNCCL::ProcessGroupNCCL(
             << ", TORCH_NCCL_HEARTBEAT_TIMEOUT_SEC: " << heartbeatTimeoutInSec_
             << ", TORCH_NCCL_TRACE_BUFFER_SIZE: " << ncclTraceBufferSize_
             << ", TORCH_NCCL_COORD_CHECK_MILSEC: " << coordCheckIntervalMilSec_
-            << ", TORCH_NCCL_NAN_CHECK: " << enableNanCheck_
-            << ", PG Name: " << options_->group_name;
+            << ", TORCH_NCCL_NAN_CHECK: " << enableNanCheck_;
 
   if (options_->global_ranks_in_group.empty()) {
     this->globalRankStart = 0;
@@ -1119,13 +1121,15 @@ ProcessGroupNCCL::~ProcessGroupNCCL() {
   LOG(INFO) << logPrefix() << "ProcessGroupNCCL destructor entered.";
 
   if (!terminateProcessGroup_.load()) {
-    LOG(WARNING) << c10::str(
-        "WARNING: process group has NOT been destroyed before it is being destructed. ",
-        "On normal program exit, the application should call destroy_process_group to ",
-        "ensure that any pending NCCL data transfers have finished in this process. "
-        "In rare cases this process can exit before this point and block the progress of "
-        "another member of the process group. This constraint has always been present, "
-        " but this warning has only been added since PyTorch 2.4");
+    if (rank_ % localDeviceCount_ == 0) {
+      TORCH_WARN_ONCE(
+          "WARNING: process group has NOT been destroyed before we destruct ProcessGroupNCCL. ",
+          "On normal program exit, the application should call destroy_process_group to ",
+          "ensure that any pending NCCL operations have finished in this process. "
+          "In rare cases this process can exit before this point and block the progress of "
+          "another member of the process group. This constraint has always been present, "
+          " but this warning has only been added since PyTorch 2.4");
+    }
     // If user haven't explicitly destroy/shutdown process group, destructor
     // needs to do so
     shutdown();
diff --git a/torch/csrc/distributed/c10d/ProcessGroupNCCL.hpp b/torch/csrc/distributed/c10d/ProcessGroupNCCL.hpp
@@ -1093,6 +1093,9 @@ class TORCH_API ProcessGroupNCCL : public Backend {
   std::string logPrefix_;
 
   c10::intrusive_ptr<intra_node_comm::IntraNodeComm> intraNodeComm_;
+
+  // Number of devices on this node.
+  int localDeviceCount_{0};
 };
 
 TORCH_API std::string dump_nccl_trace();
