From: normalperson@...
Date: 2014-09-08T20:49:05+00:00
Subject: [ruby-core:64874] [ruby-trunk - Bug #10212] MRI is not for lambda	calculus

Issue #10212 has been updated by Eric Wong.


 SASADA Koichi <ko1@atdot.net> wrote:
 > Cool. Could you commit it?
 
 Done, r47453.
 
 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...
 
 clear	108.073316744
 clear	105.554970603
 clear	105.501751921
 nozero	99.350965249
 nozero	96.923739953
 nozero	100.743984655
 
 -----------------------------------------------------------
 raw data:
 
 [["app_lc_fizzbuzz",
   [[108.073316744, 105.554970603, 105.501751921],
    [99.350965249, 96.923739953, 100.743984655]]]]
 
 Elapsed time: 616.150981421 (sec)
 -----------------------------------------------------------
 benchmark results:
 minimum results in each 3 measurements.
 Execution time (sec)
 name	clear	nozero
 app_lc_fizzbuzz	105.502	96.924
 
 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-48737

* 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.




-- 
https://bugs.ruby-lang.org/