[pypy-issue] Issue #1818: xml sax/BytesIO performance regression since 2.2.1 (pypy/pypy)

[larstiq]

New issue 1818: xml sax/BytesIO performance regression since 2.2.1
https://bitbucket.org/pypy/pypy/issue/1818/xml-sax-bytesio-performance-regression

larstiq:

On irc IvIePhisto mentioned a performance regression. To reproduce I downloaded
https://raw.githubusercontent.com/IvIePhisto/ECoXiPy/master/tests/performance/xml_sax.py
and ran

    from timeit import repeat
    print repeat("from xml_sax import create_testdoc; create_testdoc('title', 'content', 2**4, 'text')", number=100)

There are some numbers to tweak; with these settings I got on my linux32 laptop:

    pypy 2.2.1
    [1.6042330265045166, 0.6979169845581055, 0.8283989429473877]

    pypy 8a9c64ba35dc
    [27.671435832977295, 32.030592918395996, 36.68885684013367]