Sync HIP documentation 2025-10-20 (#1258)

* Add examples to tools folder
* Correct P2P memory access section
* Sync poriting guide
* Add HIP Graph tutorial
* Add hint about using amdgpu-dkms for IPC API
* Add a few more env variables

projects/hip/docs/tools/example_codes/launch_bounds.hip

@@ -0,0 +1,91 @@
+// MIT License
+//
+// Copyright (c) 2025 Advanced Micro Devices, Inc. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+// [sphinx-start]
+#include <hip/hip_runtime.h>
+
+#include <iostream>
+
+#define HIP_CHECK(expression)                                \
+{                                                            \
+    const hipError_t err = expression;                       \
+    if(err != hipSuccess)                                    \
+    {                                                        \
+        std::cerr << "HIP error: " << hipGetErrorString(err) \
+            << " at " << __LINE__ << "\n";                   \
+    }                                                        \
+}
+
+// Performs a simple initialization of an array with the thread's index variables.
+// This function is only available in device code.
+__device__ void init_array(float * const a, const unsigned int arraySize)
+{
+    // globalIdx uniquely identifies a thread in a 1D launch configuration.
+    const int globalIdx = threadIdx.x + blockIdx.x * blockDim.x;
+    // Each thread initializes a single element of the array.
+    if(globalIdx < arraySize)
+    {
+        a[globalIdx] = globalIdx;
+    }
+}
+
+// Rounds a value up to the next multiple.
+// This function is available in host and device code.
+__host__ __device__ constexpr int round_up_to_nearest_multiple(int number, int multiple)
+{
+    return (number + multiple - 1)/multiple;
+}
+
+__global__
+__launch_bounds__(512, 4) // This kernel requires at most 512 threads per block and at least 4 warps per execution unit.
+void example_kernel(float * const a, const unsigned int N)
+{
+    // Initialize array.
+    init_array(a, N);
+    // Perform additional work:
+    // - work with the array
+    // - use the array in a different kernel
+    // - ...
+}
+
+int main()
+{
+    constexpr int N = 100000000; // problem size
+    constexpr int blockSize = 256; //configurable block size
+
+    //needed number of blocks for the given problem size
+    constexpr int gridSize = round_up_to_nearest_multiple(N, blockSize);
+
+    float *a;
+    // allocate memory on the GPU
+    HIP_CHECK(hipMalloc(&a, sizeof(*a) * N));
+
+    std::cout << "Launching kernel." << std::endl;
+    example_kernel<<<dim3(gridSize), dim3(blockSize), 0/*example doesn't use shared memory*/, 0/*default stream*/>>>(a, N);
+    // make sure kernel execution is finished by synchronizing. The CPU can also
+    // execute other instructions during that time
+    HIP_CHECK(hipDeviceSynchronize());
+    std::cout << "Kernel execution finished." << std::endl;
+
+    HIP_CHECK(hipFree(a));
+}
+// [sphinx-end]