test.

src/common/device_vector.cuh

@@ -389,7 +389,6 @@ using caching_device_vector = thrust::device_vector<T,  XGBCachingDeviceAllocato
  */
 class LoggingResource : public rmm::mr::device_memory_resource {
   rmm::mr::device_memory_resource *mr_{rmm::mr::get_current_device_resource()};
-  std::mutex lock_;
 
  public:
   LoggingResource() = default;
@@ -407,10 +406,6 @@ class LoggingResource : public rmm::mr::device_memory_resource {
   }
 
   void *do_allocate(std::size_t bytes, rmm::cuda_stream_view stream) override {  // NOLINT
-    std::unique_lock<std::mutex> guard{lock_, std::defer_lock};
-    if (xgboost::ConsoleLogger::ShouldLog(xgboost::ConsoleLogger::LV::kDebug)) {
-      guard.lock();
-    }
     try {
       auto const ptr = mr_->allocate(bytes, stream);
       GlobalMemoryLogger().RegisterAllocation(ptr, bytes);
@@ -423,10 +418,6 @@ class LoggingResource : public rmm::mr::device_memory_resource {
 
   void do_deallocate(void *ptr, std::size_t bytes,  // NOLINT
                      rmm::cuda_stream_view stream) override {
-    std::unique_lock<std::mutex> guard{lock_, std::defer_lock};
-    if (xgboost::ConsoleLogger::ShouldLog(xgboost::ConsoleLogger::LV::kDebug)) {
-      guard.lock();
-    }
     mr_->deallocate(ptr, bytes, stream);
     GlobalMemoryLogger().RegisterDeallocation(ptr, bytes);
   }

tests/cpp/common/test_device_vector.cu

@@ -2,6 +2,7 @@
  * Copyright 2024, XGBoost Contributors
  */
 #include <gtest/gtest.h>
+#include <thread>  // for thread
 
 #include <numeric>                     // for iota
 #include <thrust/detail/sequence.inl>  // for sequence
@@ -115,4 +116,22 @@ TEST(TestVirtualMem, Version) {
     ASSERT_FALSE(pinned.IsVm());
   }
 }
+
+TEST(AtomitFetch, Max) {
+  auto n_threads = std::thread::hardware_concurrency();
+  std::vector<std::thread> threads;
+  std::atomic<std::int64_t> n{0};
+  decltype(n)::value_type add = 64;
+  for (decltype(n_threads) t = 0; t < n_threads; ++t) {
+    threads.emplace_back([=, &n] {
+      for (std::size_t i = 0; i < add; ++i) {
+        detail::AtomicFetchMax(n, static_cast<std::int64_t>(t + i));
+      }
+    });
+  }
+  for (auto& t : threads) {
+    t.join();
+  }
+  ASSERT_EQ(n, n_threads - 1 + add - 1);  // 0-based indexing
+}
 }  // namespace dh