Drop the size cap, keep the is_file() guard only

Author: tonghuaroot

Lib/profiling/sampling/heatmap_collector.py

@@ -783,12 +783,10 @@ def _generate_file_html(self, output_path: Path, filename: str,
                           line_counts: Dict[int, int], self_counts: Dict[int, int],
                           file_stat: FileStats):
         """Generate HTML for a single source file with heatmap coloring."""
-        _MAX_SOURCE_SIZE = 10 * 1024 * 1024
         source_lines = [f"# Source file not available: {filename}"]
         try:
             resolved = Path(filename).resolve()
-            if (resolved.is_file()
-                    and resolved.stat().st_size <= _MAX_SOURCE_SIZE):
+            if resolved.is_file():
                 source_lines = resolved.read_text(
                     encoding='utf-8', errors='replace').splitlines()
         except (IOError, OSError):

Lib/test/test_profiling/test_heatmap.py

@@ -642,29 +642,6 @@ def test_export_skips_nonexistent_source(self):
                 content = f.read()
             self.assertIn('Source file not available', content)
 
-    def test_export_caps_oversized_source(self):
-        """Source files larger than the cap produce a placeholder."""
-        collector = HeatmapCollector(sample_interval_usec=100)
-
-        big_file = os.path.join(self.test_dir, 'big.py')
-        with open(big_file, 'w') as f:
-            f.write('x = 1\n' * 2_000_000)
-
-        frames = [(big_file, (1, 1, -1, -1), 'f', None)]
-        collector.process_frames(frames, thread_id=1)
-
-        output_path = os.path.join(self.test_dir, 'big_src')
-
-        with captured_stdout(), captured_stderr():
-            collector.export(output_path)
-
-        html_files = [f for f in os.listdir(output_path)
-                      if f.startswith('file_') and f.endswith('.html')]
-        if html_files:
-            with open(os.path.join(output_path, html_files[0]),
-                      'r', encoding='utf-8') as f:
-                content = f.read()
-            self.assertIn('Source file not available', content)
 
 
 class MockFrameInfo:

Misc/NEWS.d/next/Library/2026-07-17-12-00-00.gh-issue-153838.HmCp5s.rst

@@ -1,2 +1,2 @@
-Skip non-regular and oversized files in the ``profiling.sampling`` heatmap
-exporter instead of reading them unconditionally.  Patch by tonghuaroot.
+Skip non-regular files in the ``profiling.sampling`` heatmap exporter
+instead of reading them unconditionally.  Patch by tonghuaroot.