From: Xavier Shay <xavier-list@...>
Date: 2011-05-31T07:07:28+09:00
Subject: [ruby-core:36599] Re: [Ruby 1.9 - Bug #3924] Performance bug (in require?)



On 31/05/11 1:16 AM, Yusuke ENDOH wrote:
> Hello, Xavier
>
> http://rhnh.net/2011/05/28/speeding-up-rails-startup-time
>
> In the above article, you said that the bottleneck is to find
> $LOADED_FEATURES in linear, but I doubt it.  If you are right,
> 1.8 should be also slow because 1.8 uses the same algorithm.
> Thus, I guess there is another bottleneck.
1.8 actually does exhibit the same performance curve, just over a 
greater value of N. See this graph (x-axis doubled from other benchmarks)

https://gist.github.com/c8d0d422a9203e1fe492#gistcomment-30971

I don't doubt there are other bottlenecks too though.

>
>
> I tried your patch and test in https://gist.github.com/985224
> on Ubuntu.
> I could confirm that trunk is twice slower than 1.9.2p180.
> But I couldn't confirm that the speed up by your patch.
> I also performed the same benchmark after "gem install rails",
> but there is no difference.
In that case perhaps it is related to the CASEFOLD_FILESYSTEM? I have 
been benchmarking on OSX.

A related change was reverted recently in r31692.

Cheers,
Xavier