[Python-Dev] insertdict slower?
Fri, 2 Feb 2001 10:54:42 -0500 (EST)
>>>>> "TP" == Tim Peters <email@example.com> writes:
>> I was curious about what the DictCreation microbenchmark in
>> pybench was slower (about 15%) with 2.1 than with 2.0. I ran
>> both with profiling enabled (-pg, no -O) and see that insertdict
>> is a fair bit slower in 2.1. Anyone with dict implementation
>> expertise want to hazard a guess about this?
TP> You don't need to be an expert for this one: just look at the
TP> code! There's nothing to it, and not even a comment has changed
TP> in insertdict since 2.0. I don't believe the profile.
TP> So you're looking at a buggy profiler, a buggy profiling
TP> procedure, or a Cache Mystery (the catch-all excuse for anything
TP> that's incomprehensible without HW-level monitoring tools).
I wanted to be sure that some other change to the dictionary code
didn't have the unintended consequence of slowing down insertdict.
There is a real and measurable slowdown in MAL's DictCreation
microbenchmark, which needs to be explained somehow. insertdict
sounds more plausible than many other explanations. But I don't have
any more time to think about this before the release.