Make the formula for this estimate more explicit
diff --git a/Lib/test/test_bigmem.py b/Lib/test/test_bigmem.py
index 08a0553..2f50344 100644
--- a/Lib/test/test_bigmem.py
+++ b/Lib/test/test_bigmem.py
@@ -374,7 +374,7 @@
# suffer for the list size. (Otherwise, it'd cost another 48 times
# size in bytes!) Nevertheless, a list of size takes
# 8*size bytes.
- @bigmemtest(size=_2G + 5, memuse=10)
+ @bigmemtest(size=_2G + 5, memuse=2 * ascii_char_size + 8)
def test_split_large(self, size):
_ = self.from_latin1
s = _(' a') * size + _(' ')