On 6 October 2011 21:56, Vitja Makarov <vitja.maka...@gmail.com> wrote: > 2011/10/6 mark florisson <markflorisso...@gmail.com>: >> On 6 October 2011 07:46, Stefan Behnel <stefan...@behnel.de> wrote: >>> mark florisson, 05.10.2011 15:53: >>>> >>>> On 5 October 2011 08:16, Stefan Behnel wrote: >>>>> >>>>> mark florisson, 04.10.2011 23:19: >>>>>> >>>>>> Another issue is that Cython compile time is increasing with the >>>>>> addition of control flow and cython utilities. If you use fused types >>>>>> you're also going to combinatorially add more compile time. >>>>> >>>>> I don't see that locally - a compiled Cython is hugely fast for me. In >>>>> comparison, the C compiler literally takes ages to compile the result. An >>>>> external shared library may or may not help with both - in particular, it >>>>> is >>>>> not clear to me what makes the C compiler slow. If the compile time is >>>>> dominated by the number of inlined functions (which is not unlikely), a >>>>> shared library + header file will not make a difference. >>>> >>>> Have you tried with the memoryviews merged? >>> >>> No. I didn't expect the difference to be quite that large. >>> >>> >>>> e.g. if I have this code: >>>> >>>> from libc.stdlib cimport malloc >>>> cdef int[:] slice =<int[:10]> <int *> malloc(sizeof(int) * 10) >>>> >>>> [0] [14:45] ~ ➤ time cython test.pyx >>>> cython test.pyx 2.61s user 0.08s system 99% cpu 2.695 total >>>> [0] [14:45] ~ ➤ time zsh compile >>>> zsh compile 1.88s user 0.06s system 99% cpu 1.946 total >>>> >>>> where 'compile' is the script that invoked the same gcc command >>>> distutils uses. As you can see it took more than 2.5 seconds to >>>> compile this code (simply because the memoryview utilities get >>>> included). >>> >>> Ok, that hints at serious performance problems. Could you profile it to see >>> where the issues are? Is it more that the code is loaded from an external >>> file? Or the fact that more utility code is parsed than necessary? >> >> I haven't profiled it yet (I'll do that), but I'm fairly sure it's the >> parsing of Cython utility files (not the loading). Maybe Tempita also >> adds to the overhead, I'll find out. >> > > Compiling this regex gives 5ms instead of 10ms on my machine > > https://github.com/cython/cython/blob/master/Cython/Compiler/Code.py#L85 > > And on your example gives 3% speedup >
Sorry, which code gets you 10ms? Also, is this about loading + regex matching, or just about compiling the pattern? In any case, libcython would solve these issues. Profiling will still be useful though. >>> It's certainly not obvious why the inclusion of static code, even from an >>> external file, should make any difference. >>> >>> That being said, it's not we were lacking the infrastructure for making >>> Python code run faster ... >>> >> >> Heh, indeed. In this case I think caching will solve all our problems. >> >>>>>> I'm sure >>>>>> this came up earlier, but I really think we should have a libcython >>>>>> and a cython.h. libcython (a shared library) should contain any common >>>>>> Cython-specific code not meant to be inlined, and cython.h any types, >>>>>> macros and inline functions etc. >>>>> >>>>> This has a couple of implications though. In order to support this on the >>>>> user side, we have to build one shared library per installed package in >>>>> order to avoid any Cython versioning issues. Just installing a versioned >>>>> "libcython_x.y.z.so" globally isn't enough, especially during >>>>> development, >>>>> but also at deployment time. Different packages may use different CFLAGS >>>>> or >>>>> Cython options, which may have an impact on the result. Encoding all >>>>> possible factors in the file name will be cumbersome and may mean that we >>>>> still end up with a number of installed Cython libraries that correlates >>>>> with the number of installed Cython based packages. >>>> >>>> Hm, I think the CFLAGS are important so long as they are compatible >>>> with Python. When the user compiles a Cython extension module with >>>> extra CFLAGS, this doesn't affect libpython. Similarly, the Cython >>>> utilities are really not the user's responsibility, so libcython >>>> doesn't need to be compiled with the same flags as the extension >>>> module. If still wanted, the user could either recompile python with >>>> different CFLAGS (which means libcython will get those as well), or >>>> not use libcython at all. CFLAGS should really only pertain to user >>>> code, not to the Cython library, which the user shouldn't be concerned >>>> about. >>> >>> Well, it's either the user or the OS distribution that installs (and >>> potentially builds) the libraries. That already makes it two responsible >>> entities for many systems that have to agree on what gets installed in what >>> way. I'm just saying, don't underestimate the details in world wide >>> deployments. >>> > > > > -- > vitja. > _______________________________________________ > cython-devel mailing list > cython-devel@python.org > http://mail.python.org/mailman/listinfo/cython-devel > _______________________________________________ cython-devel mailing list cython-devel@python.org http://mail.python.org/mailman/listinfo/cython-devel
