[clang] [amdgpu-arch] Replcae use of HSA with reading sysfs directly (PR #116651)

via cfe-commits cfe-commits at lists.llvm.org
Mon Nov 18 08:40:01 PST 2024


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Joseph Huber (jhuber6)

<details>
<summary>Changes</summary>

Summary:
For Linux systems, we currently use the HSA library to determine the
installed GPUs. However, this isn't really necessary and adds a
dependency on the HSA runtime as well as a lot of overhead. Instead,
this patch uses the `sysfs` interface exposed by `amdkfd` to do this
directly.


---
Full diff: https://github.com/llvm/llvm-project/pull/116651.diff


4 Files Affected:

- (modified) clang/tools/amdgpu-arch/AMDGPUArch.cpp (+2-2) 
- (removed) clang/tools/amdgpu-arch/AMDGPUArchByHSA.cpp (-122) 
- (added) clang/tools/amdgpu-arch/AMDGPUArchByKFD.cpp (+74) 
- (modified) clang/tools/amdgpu-arch/CMakeLists.txt (+1-1) 


``````````diff
diff --git a/clang/tools/amdgpu-arch/AMDGPUArch.cpp b/clang/tools/amdgpu-arch/AMDGPUArch.cpp
index 7ae57b7877e1fe..6c10cbc5c46a83 100644
--- a/clang/tools/amdgpu-arch/AMDGPUArch.cpp
+++ b/clang/tools/amdgpu-arch/AMDGPUArch.cpp
@@ -25,7 +25,7 @@ static void PrintVersion(raw_ostream &OS) {
   OS << clang::getClangToolFullVersion("amdgpu-arch") << '\n';
 }
 
-int printGPUsByHSA();
+int printGPUsByKFD();
 int printGPUsByHIP();
 
 int main(int argc, char *argv[]) {
@@ -45,7 +45,7 @@ int main(int argc, char *argv[]) {
   }
 
 #ifndef _WIN32
-  if (!printGPUsByHSA())
+  if (!printGPUsByKFD())
     return 0;
 #endif
 
diff --git a/clang/tools/amdgpu-arch/AMDGPUArchByHSA.cpp b/clang/tools/amdgpu-arch/AMDGPUArchByHSA.cpp
deleted file mode 100644
index 432f2c414ed244..00000000000000
--- a/clang/tools/amdgpu-arch/AMDGPUArchByHSA.cpp
+++ /dev/null
@@ -1,122 +0,0 @@
-//===- AMDGPUArchByHSA.cpp - list AMDGPU installed ------*- C++ -*---------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements a tool for detecting name of AMDGPU installed in system
-// using HSA on Linux. This tool is used by AMDGPU OpenMP and HIP driver.
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/Basic/Version.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/DynamicLibrary.h"
-#include "llvm/Support/Error.h"
-#include "llvm/Support/raw_ostream.h"
-#include <memory>
-#include <string>
-#include <vector>
-
-using namespace llvm;
-
-typedef enum {
-  HSA_STATUS_SUCCESS = 0x0,
-} hsa_status_t;
-
-typedef enum {
-  HSA_DEVICE_TYPE_CPU = 0,
-  HSA_DEVICE_TYPE_GPU = 1,
-} hsa_device_type_t;
-
-typedef enum {
-  HSA_AGENT_INFO_NAME = 0,
-  HSA_AGENT_INFO_DEVICE = 17,
-} hsa_agent_info_t;
-
-typedef struct hsa_agent_s {
-  uint64_t handle;
-} hsa_agent_t;
-
-hsa_status_t (*hsa_init)();
-hsa_status_t (*hsa_shut_down)();
-hsa_status_t (*hsa_agent_get_info)(hsa_agent_t, hsa_agent_info_t, void *);
-hsa_status_t (*hsa_iterate_agents)(hsa_status_t (*)(hsa_agent_t, void *),
-                                   void *);
-
-constexpr const char *DynamicHSAPath = "libhsa-runtime64.so";
-
-llvm::Error loadHSA() {
-  std::string ErrMsg;
-  auto DynlibHandle = std::make_unique<llvm::sys::DynamicLibrary>(
-      llvm::sys::DynamicLibrary::getPermanentLibrary(DynamicHSAPath, &ErrMsg));
-  if (!DynlibHandle->isValid()) {
-    return llvm::createStringError(llvm::inconvertibleErrorCode(),
-                                   "Failed to 'dlopen' %s", DynamicHSAPath);
-  }
-#define DYNAMIC_INIT(SYMBOL)                                                   \
-  {                                                                            \
-    void *SymbolPtr = DynlibHandle->getAddressOfSymbol(#SYMBOL);               \
-    if (!SymbolPtr)                                                            \
-      return llvm::createStringError(llvm::inconvertibleErrorCode(),           \
-                                     "Failed to 'dlsym' " #SYMBOL);            \
-    SYMBOL = reinterpret_cast<decltype(SYMBOL)>(SymbolPtr);                    \
-  }
-  DYNAMIC_INIT(hsa_init);
-  DYNAMIC_INIT(hsa_shut_down);
-  DYNAMIC_INIT(hsa_agent_get_info);
-  DYNAMIC_INIT(hsa_iterate_agents);
-#undef DYNAMIC_INIT
-  return llvm::Error::success();
-}
-
-static hsa_status_t iterateAgentsCallback(hsa_agent_t Agent, void *Data) {
-  hsa_device_type_t DeviceType;
-  hsa_status_t Status =
-      hsa_agent_get_info(Agent, HSA_AGENT_INFO_DEVICE, &DeviceType);
-
-  // continue only if device type if GPU
-  if (Status != HSA_STATUS_SUCCESS || DeviceType != HSA_DEVICE_TYPE_GPU) {
-    return Status;
-  }
-
-  std::vector<std::string> *GPUs =
-      static_cast<std::vector<std::string> *>(Data);
-  char GPUName[64];
-  Status = hsa_agent_get_info(Agent, HSA_AGENT_INFO_NAME, GPUName);
-  if (Status != HSA_STATUS_SUCCESS) {
-    return Status;
-  }
-  GPUs->push_back(GPUName);
-  return HSA_STATUS_SUCCESS;
-}
-
-int printGPUsByHSA() {
-  // Attempt to load the HSA runtime.
-  if (llvm::Error Err = loadHSA()) {
-    logAllUnhandledErrors(std::move(Err), llvm::errs());
-    return 1;
-  }
-
-  hsa_status_t Status = hsa_init();
-  if (Status != HSA_STATUS_SUCCESS) {
-    return 1;
-  }
-
-  std::vector<std::string> GPUs;
-  Status = hsa_iterate_agents(iterateAgentsCallback, &GPUs);
-  if (Status != HSA_STATUS_SUCCESS) {
-    return 1;
-  }
-
-  for (const auto &GPU : GPUs)
-    llvm::outs() << GPU << '\n';
-
-  if (GPUs.size() < 1)
-    return 1;
-
-  hsa_shut_down();
-  return 0;
-}
diff --git a/clang/tools/amdgpu-arch/AMDGPUArchByKFD.cpp b/clang/tools/amdgpu-arch/AMDGPUArchByKFD.cpp
new file mode 100644
index 00000000000000..c7590572de63d4
--- /dev/null
+++ b/clang/tools/amdgpu-arch/AMDGPUArchByKFD.cpp
@@ -0,0 +1,74 @@
+//===- AMDGPUArchByKFD.cpp - list AMDGPU installed ------*- C++ -*---------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a tool for detecting name of AMD GPUs installed in
+// system using the Linux sysfs interface for the AMD KFD driver.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/LineIterator.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include <memory>
+#include <string>
+
+using namespace llvm;
+
+constexpr const char *KFD_SYSFS_NODE_PATH =
+    "/sys/devices/virtual/kfd/kfd/topology/nodes";
+
+constexpr static long getMajor(long Ver) { return (Ver / 10000) % 100; }
+constexpr static long getMinor(long Ver) { return (Ver / 100) % 100; }
+constexpr static long getStep(long Ver) { return Ver % 100; }
+
+int printGPUsByKFD() {
+  SmallVector<std::pair<long, long>> Devices;
+  std::error_code EC;
+  for (sys::fs::directory_iterator Begin(KFD_SYSFS_NODE_PATH, EC), End;
+       Begin != End; Begin.increment(EC)) {
+    if (EC)
+      return 1;
+
+    long Node = 0;
+    if (sys::path::stem(Begin->path()).consumeInteger(10, Node))
+      return 1;
+
+    SmallVector<char> Path(Begin->path().begin(), Begin->path().end());
+    sys::path::append(Path, "properties");
+
+    ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+        MemoryBuffer::getFileOrSTDIN(Path);
+    if (std::error_code EC = BufferOrErr.getError())
+      return 1;
+
+    long GFXVersion = 0;
+    for (line_iterator Lines(**BufferOrErr, false); !Lines.is_at_end();
+         ++Lines) {
+      if (Lines->starts_with("gfx_target_version")) {
+        if (Lines->drop_front(sizeof("gfx_target_version"))
+                .consumeInteger(10, GFXVersion))
+          return 1;
+        break;
+      }
+    }
+
+    // If this is zero the node is a CPU.
+    if (GFXVersion == 0)
+      continue;
+    Devices.emplace_back(Node, GFXVersion);
+  }
+
+  // Sort the devices by their node to make sure it prints in order.
+  llvm::sort(Devices, [](auto &L, auto &R) { return L.first < R.first; });
+  for (const auto &[Node, GFXVersion] : Devices)
+    std::fprintf(stdout, "gfx%ld%ld%lx\n", getMajor(GFXVersion),
+                 getMinor(GFXVersion), getStep(GFXVersion));
+
+  return 0;
+}
diff --git a/clang/tools/amdgpu-arch/CMakeLists.txt b/clang/tools/amdgpu-arch/CMakeLists.txt
index 1657c701251308..c4c8de614565a7 100644
--- a/clang/tools/amdgpu-arch/CMakeLists.txt
+++ b/clang/tools/amdgpu-arch/CMakeLists.txt
@@ -8,6 +8,6 @@
 
 set(LLVM_LINK_COMPONENTS Support)
 
-add_clang_tool(amdgpu-arch AMDGPUArch.cpp AMDGPUArchByHSA.cpp AMDGPUArchByHIP.cpp)
+add_clang_tool(amdgpu-arch AMDGPUArch.cpp AMDGPUArchByKFD.cpp AMDGPUArchByHIP.cpp)
 
 target_link_libraries(amdgpu-arch PRIVATE clangBasic)

``````````

</details>


https://github.com/llvm/llvm-project/pull/116651


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