On 10-01-22 02:53:21, Collin Winter wrote: > On Thu, Jan 21, 2010 at 11:37 PM, Glyph Lefkowitz > <gl...@twistedmatrix.com> wrote: > > > > On Jan 21, 2010, at 6:48 PM, Collin Winter wrote: ... > > There's been a recent thread on our mailing list about a patch that > > dramatically reduces the memory footprint of multiprocess > > concurrency by separating reference counts from objects. ...
Currently, CPython gets a performance advantage from having reference counts hot in the cache when the referenced object is used. There is still the write pressure from updating the counts. With separate reference counts, an extra cache line must be loaded from memory (it is unlikely to be in the cache unless the program is trivial). I see from the referenced posting that this is a 10% speed hit (the poster attributes the hit to extra instructions). Perhaps the speed and memory hits could be minimized by only doing this for some objects? Only objects that are fully shared (such as read- only data) benefit from this change. I don't know but shared objects may already be treated separately. ... > The data I've seen comes from > http://groups.google.com/group/comp.lang.python/msg/c18b671f2c4fef9e: ... -- ____________________________________________________________________ TonyN.:' <mailto:tonynel...@georgeanelson.com> ' <http://www.georgeanelson.com/> _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
