On 28 January 2012 18:38, Stefan Behnel <stefan...@behnel.de> wrote: > Stefan Behnel, 27.01.2012 09:02: >> any exception *propagation* is >> still substantially slower than necessary, and that's a general issue. > > Here's a general take on a code object cache for exception propagation. > > https://github.com/scoder/cython/commit/ad18e0208 > > When I raise an exception in test code that propagates through a Python > call hierarchy of four functions before being caught, the cache gives me > something like a 2x speedup in total. Not bad. When I do the same for cdef > functions, it's more like 4-5x. > > The main idea is to cache the objects in a reallocable C array and bisect > into it based on the C code "__LINE__" of the exception, which should be > unique enough for a given module. > > It's a global cache that doesn't limit the lifetime of code objects (well, > up to the lifetime of the module, obviously). I don't know if that's a > problem because the number of code objects is only bounded by the number of > exception origination points in the C source code, which is usually quite > large. However, only a tiny fraction of those will ever raise or propagate > an exception in practice, so the real number of cached code objects will be > substantially smaller. > > Maybe thorough test suites with lots of failure testing would notice a > difference in memory consumption, even though a single code objects isn't > all that large either... > > What do you think? > > Stefan > _______________________________________________ > cython-devel mailing list > cython-devel@python.org > http://mail.python.org/mailman/listinfo/cython-devel
Nice. I have a question, couldn't you save the frame object instead of the code object? I do think PyCodeObject is rather large, on my 64 bit machine it is 120 bytes, not accounting for any of the objects it holds (not saying that's a problem, just pointing it out). Would it help if we would pass in the position information string object constant, to avoid the PyString_Format? That optimization would only save 14% though. But additionally, the function name could be a string object constant, which could be shared by all exceptions in one function, avoiding another PyString_FromString. _______________________________________________ cython-devel mailing list cython-devel@python.org http://mail.python.org/mailman/listinfo/cython-devel
