Determine total memory without psutil (#12787)

Author: cbrnr

doc/changes/devel/12787.other.rst

@@ -0,0 +1 @@
+Use custom code in :func:`mne.sys_info` to get the amount of physical memory and a more informative CPU name instead of using the ``psutil`` package, by `Clemens Brunner`_.

mne/utils/config.py

@@ -30,6 +30,10 @@
 _temp_home_dir = None
 
 
+class UnknownPlatformError(Exception):
+    """Exception raised for unknown platforms."""
+
+
 def set_cache_dir(cache_dir):
     """Set the directory to be used for temporary file storage.
 
@@ -605,6 +609,47 @@ def _get_gpu_info():
     return out
 
 
+def _get_total_memory():
+    """Return the total memory of the system in bytes."""
+    if platform.system() == "Windows":
+        o = subprocess.check_output(
+            [
+                "powershell.exe",
+                "(Get-CimInstance Win32_ComputerSystem).TotalPhysicalMemory",
+            ]
+        ).decode()
+        total_memory = int(o)
+    elif platform.system() == "Linux":
+        o = subprocess.check_output(["free", "-b"]).decode()
+        total_memory = int(o.splitlines()[1].split()[1])
+    elif platform.system() == "Darwin":
+        o = subprocess.check_output(["sysctl", "hw.memsize"]).decode()
+        total_memory = int(o.split(":")[1].strip())
+    else:
+        raise UnknownPlatformError("Could not determine total memory")
+
+    return total_memory
+
+
+def _get_cpu_brand():
+    """Return the CPU brand string."""
+    if platform.system() == "Windows":
+        o = subprocess.check_output(
+            ["powershell.exe", "(Get-CimInstance Win32_Processor).Name"]
+        ).decode()
+        cpu_brand = o.strip().splitlines()[-1]
+    elif platform.system() == "Linux":
+        o = subprocess.check_output(["grep", "model name", "/proc/cpuinfo"]).decode()
+        cpu_brand = o.splitlines()[0].split(": ")[1]
+    elif platform.system() == "Darwin":
+        o = subprocess.check_output(["sysctl", "machdep.cpu"]).decode()
+        cpu_brand = o.split("brand_string: ")[1].strip()
+    else:
+        cpu_brand = "?"
+
+    return cpu_brand
+
+
 def sys_info(
     fid=None,
     show_paths=False,
@@ -656,15 +701,20 @@ def sys_info(
     out("Platform".ljust(ljust) + platform_str + "\n")
     out("Python".ljust(ljust) + str(sys.version).replace("\n", " ") + "\n")
     out("Executable".ljust(ljust) + sys.executable + "\n")
-    out("CPU".ljust(ljust) + f"{platform.processor()} ")
+    try:
+        cpu_brand = _get_cpu_brand()
+    except Exception:
+        cpu_brand = "?"
+    out("CPU".ljust(ljust) + f"{cpu_brand} ")
     out(f"({multiprocessing.cpu_count()} cores)\n")
     out("Memory".ljust(ljust))
     try:
-        import psutil
-    except ImportError:
-        out('Unavailable (requires "psutil" package)')
+        total_memory = _get_total_memory()
+    except UnknownPlatformError:
+        total_memory = "?"
     else:
-        out(f"{psutil.virtual_memory().total / float(2 ** 30):0.1f} GB\n")
+        total_memory = f"{total_memory / 1024**3:.1f}"  # convert to GiB
+    out(f"{total_memory} GiB\n")
     out("\n")
     ljust -= 3  # account for +/- symbols
     libs = _get_numpy_libs()

mne/utils/tests/test_config.py

@@ -110,7 +110,7 @@ def test_sys_info_basic():
     assert "numpy" in out
     # replace all in-line whitespace with single space
     out = "\n".join(" ".join(o.split()) for o in out.splitlines())
-
+    assert "? GiB" not in out
     if platform.system() == "Darwin":
         assert "Platform macOS-" in out
     elif platform.system() == "Linux":

pyproject.toml

@@ -78,7 +78,6 @@ full-no-qt = [
     "jupyter",
     "python-picard",
     "joblib",
-    "psutil",
     "dipy",
     "vtk",
     "nilearn",
@@ -175,6 +174,7 @@ doc = [
     "intersphinx_registry>=0.2405.27",
     # https://github.com/sphinx-contrib/sphinxcontrib-towncrier/issues/92
     "towncrier<24.7",
+    "psutil",
 ]
 dev = ["mne[test,doc]", "rcssmin"]