python · nascheme · Nov 27, 2025
diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
@@ -1493,11 +1493,10 @@ def callback(ignored):
            # The free-threaded build doesn't have multiple generations, so
            # just trigger a GC manually.
            gc.collect()
-        assert not detector.gc_happened
        while not detector.gc_happened:
            i += 1
-            if i > 100000:
-                self.fail("gc didn't happen after 100000 iterations")
+            if i > 10000:
+                self.fail("gc didn't happen after 10000 iterations")
            self.assertEqual(len(ouch), 0)
            junk.append([])  # this will eventually trigger gc

@@ -1569,8 +1568,8 @@ def __del__(self):
            gc.collect()
        while not detector.gc_happened:
            i += 1
-            if i > 50000:
-                self.fail("gc didn't happen after 50000 iterations")
+            if i > 10000:
+                self.fail("gc didn't happen after 10000 iterations")
            self.assertEqual(len(ouch), 0)
            junk.append([])  # this will eventually trigger gc

@@ -1587,8 +1586,8 @@ def test_indirect_calls_with_gc_disabled(self):
        detector = GC_Detector()
        while not detector.gc_happened:
            i += 1
-            if i > 100000:
-                self.fail("gc didn't happen after 100000 iterations")
+            if i > 10000:
+                self.fail("gc didn't happen after 10000 iterations")
            junk.append([])  # this will eventually trigger gc

        try:
@@ -1598,11 +1597,11 @@ def test_indirect_calls_with_gc_disabled(self):
            detector = GC_Detector()
            while not detector.gc_happened:
                i += 1
-                if i > 100000:
+                if i > 10000:
                    break
                junk.append([])  # this may eventually trigger gc (if it is enabled)

-            self.assertEqual(i, 100001)
+            self.assertEqual(i, 10001)
        finally:
            gc.enable()


diff --git a/Python/gc.c b/Python/gc.c
@@ -1644,7 +1644,7 @@ assess_work_to_do(GCState *gcstate)
        scale_factor = 2;
    }
    intptr_t new_objects = gcstate->young.count;
-    intptr_t max_heap_fraction = new_objects*2;
+    intptr_t max_heap_fraction = new_objects*3/2;
    intptr_t heap_fraction = gcstate->heap_size / SCAN_RATE_DIVISOR / scale_factor;
    if (heap_fraction > max_heap_fraction) {
        heap_fraction = max_heap_fraction;
@@ -1659,9 +1659,6 @@ gc_collect_increment(PyThreadState *tstate, struct gc_collection_stats *stats)
    GC_STAT_ADD(1, collections, 1);
    GCState *gcstate = &tstate->interp->gc;
    gcstate->work_to_do += assess_work_to_do(gcstate);
-    if (gcstate->work_to_do < 0) {
-        return;
-    }
    untrack_tuples(&gcstate->young.head);
    if (gcstate->phase == GC_PHASE_MARK) {
        Py_ssize_t objects_marked = mark_at_start(tstate);
@@ -1705,6 +1702,7 @@ gc_collect_increment(PyThreadState *tstate, struct gc_collection_stats *stats)
    gc_collect_region(tstate, &increment, &survivors, stats);
    gc_list_merge(&survivors, visited);
    assert(gc_list_is_empty(&increment));
+    gcstate->work_to_do += gcstate->heap_size / SCAN_RATE_DIVISOR / scale_factor;
    gcstate->work_to_do -= increment_size;

    if (gc_list_is_empty(not_visited)) {