From c5346ef5527edcddf194e6d33bcde082f544e8b1 Mon Sep 17 00:00:00 2001
From: Jane Liu <janeliu@nvidia.com>
Date: Thu, 12 Sep 2024 17:34:27 -0700
Subject: [PATCH] PR #16921: [PJRT:GPU] Treat GPU collective memory space as
 device memory space

Imported from GitHub PR https://github.com/openxla/xla/pull/16921

This is a regression fix when using --xla_gpu_enable_nccl_user_buffers=true.
Return device memory space when collective memory space is used as an output on GPU.
Copybara import of the project:

--
8113e6fbe23d5902ecdd406793555c602c1b7f81 by Jane Liu <janeliu@nvidia.com>:

Treat collective memory space as device memory space when using as an output

--
b5e43d6455adc49f5ac99a9a9e95cf495eb46170 by Jane Liu <janeliu@nvidia.com>:

fix the test

Merging this change closes #16921

COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/16921 from zhenying-liu:nccl-buffer-output b5e43d6455adc49f5ac99a9a9e95cf495eb46170
PiperOrigin-RevId: 674073363
---
 xla/pjrt/gpu/se_gpu_pjrt_client_test.cc | 62 +++++++++++++++++++++++++
 xla/pjrt/pjrt_stream_executor_client.cc |  2 +
 2 files changed, 64 insertions(+)

diff --git a/xla/pjrt/gpu/se_gpu_pjrt_client_test.cc b/xla/pjrt/gpu/se_gpu_pjrt_client_test.cc
index c4d82ce9d3c4b..ac6f85bd4b950 100644
--- a/xla/pjrt/gpu/se_gpu_pjrt_client_test.cc
+++ b/xla/pjrt/gpu/se_gpu_pjrt_client_test.cc
@@ -1131,6 +1131,24 @@ constexpr char const* kD2HProgramTupleOutput = R"(
   }
 )";
 
+constexpr char const* kCollectiveMemorySpaceOutput = R"(
+
+  HloModule jit__psum, entry_computation_layout={(s32[1,4]{1,0})->s32[4]{0}}
+
+  region_0.3 {
+    Arg_0.0 = s32[] parameter(0)
+    Arg_1.0 = s32[] parameter(1)
+    ROOT add.0 = s32[] add(Arg_0.0, Arg_1.0)
+  }
+
+  ENTRY main.10_spmd {
+    param = s32[1,4]{1,0} parameter(0)
+    reshape = s32[4]{0} reshape(param)
+    ROOT all-reduce = s32[4]{0} all-reduce(reshape), channel_id=1, to_apply=region_0.3
+  }
+
+)";
+
 }  // namespace
 
 TEST(StreamExecutorGpuClientTest, ExecutePinnedHostOutputTest) {
@@ -1197,6 +1215,50 @@ TEST(StreamExecutorGpuClientTest, ExecutablePinnedHostOutputMemoryKindTest) {
   EXPECT_EQ(memory_kinds[0][0], "pinned_host");
 }
 
+// Verify the output device memory kind with collective memory space shape when
+// NCCL user buffer is enabled.
+TEST(StreamExecutorGpuClientTest,
+     ExecutableCollectiveMemoryOutputMemoryKindTest) {
+  TF_ASSERT_OK_AND_ASSIGN(auto client,
+                          GetStreamExecutorGpuClient(GpuClientOptions()));
+  xla::CompileOptions options;
+  options.executable_build_options.mutable_debug_options()
+      ->set_xla_gpu_enable_nccl_user_buffers(true);
+
+  TF_ASSERT_OK_AND_ASSIGN(
+      auto executable,
+      CompileExecutable(kCollectiveMemorySpaceOutput, *client, options));
+  std::vector<int32_t> data{1, 2, 3, 4};
+  // Build the input shape with the correct memory space set.
+  Shape shape = ShapeUtil::MakeShapeWithDenseLayout(S32, {1, 4},
+                                                    /*major_to_minor=*/{1, 0});
+  shape.mutable_layout()->set_memory_space(Layout::kDefaultMemorySpace);
+
+  auto device = client->addressable_devices()[0];
+  TF_EXPECT_OK(device->default_memory_space());
+  TF_ASSERT_OK_AND_ASSIGN(
+      auto input, client->BufferFromHostBuffer(
+                      data.data(), shape.element_type(), shape.dimensions(),
+                      /*byte_strides=*/std::nullopt,
+                      PjRtClient::HostBufferSemantics::kImmutableOnlyDuringCall,
+                      /*on_done_with_host_buffer=*/nullptr, device));
+  EXPECT_EQ(input->memory_space()->kind(), "device");
+
+  TF_ASSERT_OK_AND_ASSIGN(auto memory_kinds,
+                          executable->GetOutputMemoryKinds());
+  EXPECT_EQ(memory_kinds.size(), 1);
+  EXPECT_EQ(memory_kinds[0].size(), 1);
+  EXPECT_EQ(memory_kinds[0][0], "device");
+
+  TF_ASSERT_OK_AND_ASSIGN(
+      auto result, executable->Execute({{input.get()}}, ExecuteOptions()));
+  std::vector<std::unique_ptr<xla::PjRtBuffer>>& result_buffers = result[0];
+  EXPECT_EQ(result_buffers[0]->memory_space()->kind(), "device");
+  Shape result_shape = result_buffers[0]->on_device_shape();
+  auto memory_space = result_shape.layout().memory_space();
+  EXPECT_EQ(memory_space, 1);
+}
+
 TEST(StreamExecutorGpuClientTest,
      ExecutablePinnedHostTupleOutputMemoryKindTest) {
   TF_ASSERT_OK_AND_ASSIGN(auto client,
diff --git a/xla/pjrt/pjrt_stream_executor_client.cc b/xla/pjrt/pjrt_stream_executor_client.cc
index d79b461f1ff86..c9e1c61cd56a3 100644
--- a/xla/pjrt/pjrt_stream_executor_client.cc
+++ b/xla/pjrt/pjrt_stream_executor_client.cc
@@ -2286,6 +2286,7 @@ absl::StatusOr<std::unique_ptr<PjRtBuffer>> OutputBufferHelper(
       device->default_memory_space().value_or(nullptr);
   if (shape.has_layout()) {
     switch (shape.layout().memory_space()) {
+      case Layout::kGenericFastMemorySpace:
       case Layout::kDefaultMemorySpace:
         // Nothing to do, we have already set the default memory space.
         break;
@@ -3322,6 +3323,7 @@ absl::StatusOr<absl::string_view> MemoryKindFromSimpleShape(
   switch (shape.layout().memory_space()) {
     case Layout::kHostMemorySpace:
       return PinnedHostMemorySpace::kKind;
+    case Layout::kGenericFastMemorySpace:
     case Layout::kDefaultMemorySpace:
       return default_memory_kind;
     default: