Hey Antoine, On Thu, Jan 21, 2010 at 4:25 AM, Antoine Pitrou <solip...@pitrou.net> wrote: >> The increased memory usage comes from a) LLVM code generation, analysis >> and optimization libraries; b) native code; c) memory usage issues or >> leaks in LLVM; d) data structures needed to optimize and generate >> machine code; e) as-yet uncategorized other sources. > > Does the increase in memory occupation disappear when the JIT is disabled > from the command-line?
It does not disappear, but it is significantly reduced. Running our django benchmark against three different configurations gives me these max memory usage numbers: CPython 2.6.4: 8508 kb Unladen Swallow default: 26768 kb Unladen Swallow -j never: 15144 kb "-j never" is Unladen Swallow's flag to disable JIT compilation. As it stands right now, -j never gives a 1.76x reduction in memory usage, but is still 1.77x larger than CPython. It occurs to me that we're still doing a lot of LLVM-side initialization and setup that we don't need to do under -j never. We're also collecting runtime feedback in the eval loop, which is yet more memory usage. Optimizing this mode has not yet been a priority for us, but it seems to be the emerging consensus of python-dev that we need to give -j never some more love. There's a lot of low-hanging fruit there. I've added this information to http://code.google.com/p/unladen-swallow/issues/detail?id=123, which is our issue tracking -j never improvements. > Do you think LLVM might suffer from a lot of memory leaks? I don't know that it suffers from a lot of memory leaks, though we have certainly observed and fixed quadratic memory usage in some of the optimization passes. We've fixed all the memory leaks that Google's internal heapchecker has found. Thanks, Collin Winter _______________________________________________ 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
