我一直在测试我制作的缓存系统。其目的是加速Django Web应用程序。它将所有内容存储在内存中。根据cProfile，在我的测试中大部分时间都花在QuerySet._clone（）中，结果证明效率非常低（实际上并没有那么奇怪）。
我非常希望使用PyPy来加快速度。我有一台64位机器。然而，在安装了所有必需的库之后，事实证明PyPy编译的代码运行速度比常规Python代码慢2.5倍，而且我不知道该怎么做。代码是CPU绑定的（绝对没有数据库查询，因此IO边界不是一个选项）。单个测试运行大约10秒，所以我想JIT应该足够了。我正在使用PyPy 1.5。一个注意事项 - 我自己没有编译源代码，只是下载了一个64位的linux版本。
我想知道CPU密集型代码在PyPy下实际运行速度有多快。希望我能做些什么会阻止PyPy运行到最佳状态。
修改
确切的cPython输出：
PyPy 1.5：
3439146 function calls (3218654 primitive calls) in 19.094 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
2/1 0.000 0.000 18.956 18.956 <string>:1(<module>)
2/1 0.000 0.000 18.956 18.956 /path/to/my/project/common/integrity/models/transactions.py:200(newfn)
2/1 0.000 0.000 18.956 18.956 /path/to/my/project/common/integrity/models/transactions.py:134(recur)
2/1 0.000 0.000 18.956 18.956 /usr/local/pypy/site-packages/django/db/transaction.py:210(inner)
2/1 0.172 0.086 18.899 18.899 /path/to/my/project/common/integrity/tests/optimization.py:369(func_cached)
9990 0.122 0.000 18.632 0.002 /usr/local/pypy/site-packages/django/db/models/manager.py:131(get)
9990 0.127 0.000 16.638 0.002 /path/to/my/project/common/integrity/models/cache.py:1068(get)
9990 0.073 0.000 12.478 0.001 /usr/local/pypy/site-packages/django/db/models/query.py:547(filter)
9990 0.263 0.000 12.405 0.001 /path/to/my/project/common/integrity/models/cache.py:1047(_filter_or_exclude)
9990 0.226 0.000 12.096 0.001 /usr/local/pypy/site-packages/django/db/models/query.py:561(_filter_or_exclude)
9990 0.187 0.000 8.383 0.001 /path/to/my/project/common/integrity/models/cache.py:765(_clone)
9990 0.212 0.000 7.662 0.001 /usr/local/pypy/site-packages/django/db/models/query.py:772(_clone)
9990 1.025 0.000 7.125 0.001 /usr/local/pypy/site-packages/django/db/models/sql/query.py:226(clone)
129942/49972 1.674 0.000 6.021 0.000 /usr/local/pypy/lib-python/2.7/copy.py:145(deepcopy)
140575/110605 0.120 0.000 4.066 0.000 {len}
9990 0.182 0.000 3.972 0.000 /usr/local/pypy/site-packages/django/db/models/query.py:74(__len__)
19980 0.260 0.000 3.777 0.000 /path/to/my/project/common/integrity/models/cache.py:1062(iterator)
9990 0.255 0.000 3.154 0.000 /usr/local/pypy/site-packages/django/db/models/sql/query.py:1149(add_q)
9990 0.210 0.000 3.073 0.000 /path/to/my/project/common/integrity/models/cache.py:973(_query)
9990 0.371 0.000 2.316 0.000 /usr/local/pypy/site-packages/django/db/models/sql/query.py:997(add_filter)
9990 0.364 0.000 2.168 0.000 /path/to/my/project/common/integrity/models/cache.py:892(_deduct)
29974/9994 0.448 0.000 2.078 0.000 /usr/local/pypy/lib-python/2.7/copy.py:234(_deepcopy_tuple)
19990 0.362 0.000 2.065 0.000 /path/to/my/project/common/integrity/models/cache.py:566(__init__)
10000 0.086 0.000 1.874 0.000 /path/to/my/project/common/integrity/models/cache.py:1090(get_query_set)
19990 0.269 0.000 1.703 0.000 /usr/local/pypy/site-packages/django/db/models/query.py:31(__init__)
9990 0.122 0.000 1.643 0.000 /path/to/my/project/common/integrity/models/cache.py:836(_deduct_recur)
19980 0.274 0.000 1.636 0.000 /usr/local/pypy/site-packages/django/utils/tree.py:55(__deepcopy__)
9990 0.607 0.000 1.458 0.000 /path/to/my/project/common/integrity/models/cache.py:789(_deduct_local)
10020 0.633 0.000 1.437 0.000 /usr/local/pypy/site-packages/django/db/models/sql/query.py:99(__init__)
129942 0.841 0.000 1.191 0.000 /usr/local/pypy/lib-python/2.7/copy.py:267(_keep_alive)
9994/9992 0.201 0.000 1.019 0.000 /usr/local/pypy/lib-python/2.7/copy.py:306(_reconstruct)
Python 2.7：
3326403 function calls (3206359 primitive calls) in 12.430 CPU seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 12.457 12.457 <string>:1(<module>)
1 0.000 0.000 12.457 12.457 /path/to/my/project/common/integrity/models/transactions.py:200(newfn)
1 0.000 0.000 12.457 12.457 /path/to/my/project/common/integrity/models/transactions.py:134(recur)
1 0.000 0.000 12.457 12.457 /usr/local/lib/python2.7/dist-packages/django/db/transaction.py:210(inner)
1 0.000 0.000 12.457 12.457 /path/to/my/project/common/integrity/models/transactions.py:165(recur2)
1 0.089 0.089 12.450 12.450 /path/to/my/project/common/integrity/tests/optimization.py:369(func_cached)
9990 0.198 0.000 12.269 0.001 /usr/local/lib/python2.7/dist-packages/django/db/models/manager.py:131(get)
9990 0.087 0.000 11.281 0.001 /path/to/my/project/common/integrity/models/cache.py:1068(get)
9990 0.040 0.000 8.161 0.001 /usr/local/lib/python2.7/dist-packages/django/db/models/query.py:547(filter)
9990 0.110 0.000 8.121 0.001 /path/to/my/project/common/integrity/models/cache.py:1047(_filter_or_exclude)
9990 0.127 0.000 7.983 0.001 /usr/local/lib/python2.7/dist-packages/django/db/models/query.py:561(_filter_or_exclude)
9990 0.100 0.000 5.593 0.001 /path/to/my/project/common/integrity/models/cache.py:765(_clone)
9990 0.122 0.000 5.125 0.001 /usr/local/lib/python2.7/dist-packages/django/db/models/query.py:772(_clone)
9990 0.405 0.000 4.899 0.000 /usr/local/lib/python2.7/dist-packages/django/db/models/sql/query.py:226(clone)
129942/49972 1.456 0.000 4.505 0.000 /usr/lib/python2.7/copy.py:145(deepcopy)
129899/99929 0.191 0.000 3.117 0.000 {len}
9990 0.111 0.000 2.968 0.000 /usr/local/lib/python2.7/dist-packages/django/db/models/query.py:74(__len__)
19980 0.070 0.000 2.843 0.000 /path/to/my/project/common/integrity/models/cache.py:1062(iterator)
9990 0.208 0.000 2.190 0.000 /path/to/my/project/common/integrity/models/cache.py:973(_query)
9990 0.182 0.000 2.114 0.000 /usr/local/lib/python2.7/dist-packages/django/db/models/sql/query.py:1149(add_q)
19984/9994 0.291 0.000 1.644 0.000 /usr/lib/python2.7/copy.py:234(_deepcopy_tuple)
9990 0.288 0.000 1.599 0.000 /usr/local/lib/python2.7/dist-packages/django/db/models/sql/query.py:997(add_filter)
9990 0.171 0.000 1.454 0.000 /path/to/my/project/common/integrity/models/cache.py:892(_deduct)
19980 0.177 0.000 1.208 0.000 /usr/local/lib/python2.7/dist-packages/django/utils/tree.py:55(__deepcopy__)
9990 0.099 0.000 1.199 0.000 /path/to/my/project/common/integrity/models/cache.py:836(_deduct_recur)
9990 0.349 0.000 1.040 0.000 /path/to/my/project/common/integrity/models/cache.py:789(_deduct_local)
答案 0 :(得分：17)
撇开PyPy可能真的对你的情况本质上较慢的事实，有一些因素可能会使它变得不必要地变慢：
您还可以查看JIT Friendliness wiki页面，了解更多关于可以使PyPy变慢的提示。 nightly build也可能更快，因为相对于1.5有许多改进。
您的堆栈（服务器，操作系统，数据库）和设置的更详细描述（您是如何基准测试？有多少查询？）将使我们能够提供更好的答案。