--- a/mercurial/revlog.py Fri Apr 13 15:32:49 2012 -0500 +++ b/mercurial/revlog.py Fri Apr 13 21:35:48 2012 -0500 @@ -812,7 +812,7 @@ else: df = self.opener(self.datafile) - readahead = max(65536, length) + readahead = max(_chunksize, length) df.seek(offset) d = df.read(readahead) df.close()