Issue #10212 has been updated by Eric Wong.


 Eric Wong <normalperson / yhbt.net> wrote:
 > I think the xcalloc was overreaching, though.
 > 
 > Removing redundant zero from env_alloc + rb_proc_alloc has a measurable
 > effect:
 > 
 > http://80x24.org/misc/m/1410209049-23179-1-git-send-email-e%4080x24.org.txt
 > 
 > Makes code a little more fragile, though, so we must be careful about
 > GC...
 
 Any comment?  I think the improvement is worth it since proc allocation
 only happens in 2 places, and env allocation in 1 place.
 
 > Speedup ratio: compare with the result of `clear' (greater is better)
 > name	nozero
 > app_lc_fizzbuzz	1.089

----------------------------------------
Bug #10212: MRI is not for lambda calculus
https://bugs.ruby-lang.org/issues/10212#change-48852

* Author: Koichi Sasada
* Status: Open
* Priority: Normal
* Assignee: Koichi Sasada
* Category: 
* Target version: current: 2.2.0
* ruby -v: ruby 2.2.0dev (2014-08-21 trunk 47241) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
 # title is joke.

I added benchmark/bm_lc_fizzbuzz.rb which solve fizz buzz program by lambda calculus.
http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=47447

(This program is closly described by ["Understanding Computation"] (http://computationbook.com/) by Tom Stuart)
([Japanese translation of this book] (http://www.oreilly.co.jp/books/9784873116976/) will be published soon)

The results of this program are:

```
jruby 1.7.12 (1.9.3p392) 2014-04-15 643e292 on OpenJDK 64-Bit Server VM 1.7.0_65-b32 [linux-amd64]
real    0m26.648s
user    0m30.091s
sys     0m4.369s

mruby 89e9df26819b9555fb790a16662f4ad2b9cbb2e2
real    0m27.145s
user    0m27.110s
sys     0m0.012s

ruby 2.2.0dev (2014-08-21 trunk 47241) [x86_64-linux]
real    1m54.648s
user    1m54.512s
sys     0m0.028s
```

It is clear that MRI is too slow.

I haven't dig details, but maybe it is because of GC perforamance. Because Proc (and Env) objects are wb-unprotected, such objects are marked on every minor GC.

This problem is not critical because MRI is not for lambda calculus :p but we can improve about it.




-- 
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