fix(Linux): cpu_count_cores() method giampaolo#2 on aarch64

psutil/_pslinux.py

@@ -694,6 +694,10 @@ def cpu_count_cores():
     # Method #2
     mapping = {}
     current_info = {}
+    # 'physical id' / 'cpu cores' not supported on e.g. aarch64
+    # https://github.com/torvalds/linux/blob/v6.9/arch/arm64/kernel/cpuinfo.c#L193-L258
+    # fall-back to processor count in this case
+    processor_count = 0
     with open_binary('%s/cpuinfo' % get_procfs_path()) as f:
         for line in f:
             line = line.strip().lower()
@@ -711,9 +715,11 @@ def cpu_count_cores():
                 if line.startswith((b'physical id', b'cpu cores')):
                     key, value = line.split(b'\t:', 1)
                     current_info[key] = int(value)
+                elif line.startswith(b'processor\t:'):
+                    processor_count += 1
 
     result = sum(mapping.values())
-    return result or None  # mimic os.cpu_count()
+    return result or processor_count or None  # mimic os.cpu_count()
 
 
 def cpu_stats():