[pypy-dev] funding/popularity?

[Armin Rigo]

Hi Dima,

On Wed, Dec 22, 2010 at 11:21 PM, Dima Tisnek <dimaqq at gmail.com> wrote:
> --- Comment #4 from Boris Zbarsky (:bz) <bzbarsky at mit.edu> 2010-12-22
> 13:43:23 PST ---
> So what I see this page do, in horizontal mode, is create 17 canvases each of
> which is width="816" height="3587".  That means that each of them has a backing
> store of 816*3587*4 = 11,707,968 bytes.  So that's about 200MB of memory usage
> right there.
>
> I have no idea why they feel a need for 17 huge canvases, but if they want
> them, that's how much memory they'll take...

That looks very similar to an issue with PyPy's own GC, in which
ctypes.create_string_buffer() returns objects which tend to be GC'ed
late.  That's because the string buffer object in ctypes appears (to
PyPy's GC) to be just a small object, even though it actually
references a potentially large piece of raw memory.  Similarly, my
vague guess about the above is that the 17*11MB of memory are hold by
17 small objects which firefox's GC think don't need to be collected
particularly aggressively.


A bientôt,

Armin.