[platform] add debug logging during inferring the device type

vllm/platforms/__init__.py

@@ -32,22 +32,25 @@ def vllm_version_matches_substr(substr: str) -> bool:
 
 def tpu_platform_plugin() -> Optional[str]:
     is_tpu = False
+    logger.debug("Checking if TPU platform is available.")
     try:
         # While it's technically possible to install libtpu on a
         # non-TPU machine, this is a very uncommon scenario. Therefore,
         # we assume that libtpu is installed if and only if the machine
         # has TPUs.
         import libtpu  # noqa: F401
         is_tpu = True
-    except Exception:
+        logger.debug("Confirmed TPU platform is available.")
+    except Exception as e:
+        logger.debug("TPU platform is not available because: %s", str(e))
         pass
 
     return "vllm.platforms.tpu.TpuPlatform" if is_tpu else None
 
 
 def cuda_platform_plugin() -> Optional[str]:
     is_cuda = False
-
+    logger.debug("Checking if CUDA platform is available.")
     try:
         from vllm.utils import import_pynvml
         pynvml = import_pynvml()
@@ -60,9 +63,19 @@ def cuda_platform_plugin() -> Optional[str]:
             # on a GPU machine, even if in a cpu build.
             is_cuda = (pynvml.nvmlDeviceGetCount() > 0
                        and not vllm_version_matches_substr("cpu"))
+            if pynvml.nvmlDeviceGetCount() <= 0:
+                logger.debug(
+                    "CUDA platform is not available because no GPU is found.")
+            if vllm_version_matches_substr("cpu"):
+                logger.debug("CUDA platform is not available because"
+                             " vLLM is built with CPU.")
+            if is_cuda:
+                logger.debug("Confirmed CUDA platform is available.")
         finally:
             pynvml.nvmlShutdown()
     except Exception as e:
+        logger.debug("Exception happens when checking CUDA platform: %s",
+                     str(e))
         if "nvml" not in e.__class__.__name__.lower():
             # If the error is not related to NVML, re-raise it.
             raise e
@@ -75,84 +88,117 @@ def cuda_is_jetson() -> bool:
                 or os.path.exists("/sys/class/tegra-firmware")
 
         if cuda_is_jetson():
+            logger.debug("Confirmed CUDA platform is available on Jetson.")
             is_cuda = True
+        else:
+            logger.debug("CUDA platform is not available because: %s", str(e))
 
     return "vllm.platforms.cuda.CudaPlatform" if is_cuda else None
 
 
 def rocm_platform_plugin() -> Optional[str]:
     is_rocm = False
-
+    logger.debug("Checking if ROCm platform is available.")
     try:
         import amdsmi
         amdsmi.amdsmi_init()
         try:
             if len(amdsmi.amdsmi_get_processor_handles()) > 0:
                 is_rocm = True
+                logger.debug("Confirmed ROCm platform is available.")
         finally:
             amdsmi.amdsmi_shut_down()
-    except Exception:
+    except Exception as e:
+        logger.debug("ROCm platform is not available because: %s", str(e))
         pass
 
     return "vllm.platforms.rocm.RocmPlatform" if is_rocm else None
 
 
 def hpu_platform_plugin() -> Optional[str]:
     is_hpu = False
+    logger.debug("Checking if HPU platform is available.")
     try:
         from importlib import util
         is_hpu = util.find_spec('habana_frameworks') is not None
-    except Exception:
+        if is_hpu:
+            logger.debug("Confirmed HPU platform is available.")
+        else:
+            logger.debug("HPU platform is not available because "
+                         "habana_frameworks is not found.")
+    except Exception as e:
+        logger.debug("HPU platform is not available because: %s", str(e))
         pass
 
     return "vllm.platforms.hpu.HpuPlatform" if is_hpu else None
 
 
 def xpu_platform_plugin() -> Optional[str]:
     is_xpu = False
-
+    logger.debug("Checking if XPU platform is available.")
     try:
         # installed IPEX if the machine has XPUs.
         import intel_extension_for_pytorch  # noqa: F401
         import oneccl_bindings_for_pytorch  # noqa: F401
         import torch
         if hasattr(torch, 'xpu') and torch.xpu.is_available():
             is_xpu = True
-    except Exception:
+            logger.debug("Confirmed XPU platform is available.")
+    except Exception as e:
+        logger.debug("XPU platform is not available because: %s", str(e))
         pass
 
     return "vllm.platforms.xpu.XPUPlatform" if is_xpu else None
 
 
 def cpu_platform_plugin() -> Optional[str]:
     is_cpu = False
+    logger.debug("Checking if CPU platform is available.")
     try:
         is_cpu = vllm_version_matches_substr("cpu")
+        if is_cpu:
+            logger.debug("Confirmed CPU platform is available because"
+                         " vLLM is built with CPU.")
         if not is_cpu:
             import platform
             is_cpu = platform.machine().lower().startswith("arm")
+            if is_cpu:
+                logger.debug("Confirmed CPU platform is available"
+                             " because the machine is ARM.")
 
-    except Exception:
+    except Exception as e:
+        logger.debug("CPU platform is not available because: %s", str(e))
         pass
 
     return "vllm.platforms.cpu.CpuPlatform" if is_cpu else None
 
 
 def neuron_platform_plugin() -> Optional[str]:
     is_neuron = False
+    logger.debug("Checking if Neuron platform is available.")
     try:
         import transformers_neuronx  # noqa: F401
         is_neuron = True
-    except ImportError:
+        logger.debug("Confirmed Neuron platform is available because"
+                     " transformers_neuronx is found.")
+    except ImportError as e:
+        logger.debug("Neuron platform is not available because: %s", str(e))
         pass
 
     return "vllm.platforms.neuron.NeuronPlatform" if is_neuron else None
 
 
 def openvino_platform_plugin() -> Optional[str]:
     is_openvino = False
+    logger.debug("Checking if OpenVINO platform is available.")
     with suppress(Exception):
         is_openvino = vllm_version_matches_substr("openvino")
+        if is_openvino:
+            logger.debug("Confirmed OpenVINO platform is available"
+                         " because vLLM is built with OpenVINO.")
+    if not is_openvino:
+        logger.debug("OpenVINO platform is not available because"
+                     " vLLM is not built with OpenVINO.")
 
     return "vllm.platforms.openvino.OpenVinoPlatform" if is_openvino else None