From: Kero van Gelder <kero@...8005.upc-a.chello.nl>
Date: 2002-12-20T08:39:57+09:00
Subject: speed differences between ruby versions


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Hello all,

In search of a bug, I created some sample code for a C-binding.
(Code attached, mkdir test/; cd test/; ruby extconf.rb; make; cd ..;
ruby test/buggy.rb)

Turns out, @home (measured with `time ruby test/buggy.rb`):
1.6.5, 1.6.8, 1.7.2 (date unknown) are fast
1.6.7 slowish (10x)
1.7.3 (dec 19) slow (>30x)

and @work:
1.6.7 (I think), 1.7.2 (date unknown) fast
1.7.3 (dec 16) slow

It is all very consistent on one machine, but I can not pinpoint what
causes it... Anyone can reproduce this? Any insights?

`ruby -rprofile` shows the difference in speed as follows (i.e. Bla#new):

fast:
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 55.97     1.36      1.36    12345     0.11     0.11  Bla#new
 43.62     2.42      1.06        1  1060.00  2420.00  Fixnum#times
  0.00     2.42      0.00        1     0.00     0.00  Class#inherited
  0.00     2.42      0.00        1     0.00     0.00  Array#allocate
  0.00     2.42      0.00       12     0.00     0.00  String#allocate
  0.00     2.42      0.00        1     0.00  2430.00  #toplevel
  0.00     2.42      0.00        1     0.00     0.00  Kernel.require

slow:
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 95.09    38.34     38.34    12345     3.11     3.11  Bla#new
  4.91    40.32      1.98        1  1980.00 40320.00  Integer#times
  0.00    40.32      0.00        1     0.00     0.00  Array#allocate
  0.00    40.32      0.00        1     0.00 40320.00  #toplevel
  0.00    40.32      0.00        1     0.00     0.00  Class#inherited
  0.00    40.32      0.00        4     0.00     0.00  String#allocate
  0.00    40.32      0.00        1     0.00     0.00  Kernel.require

Bye,
Kero.

PS: my bug turned out to be "-ldmalloc" for gcc, that solved my memory
leak, but not the speed difference.

+--- Kero ------------------------------ kero@chello.nl ---+
|  Don't split your mentality without thinking twice       |
|                          Proud like a God -- Guano Apes  |
+--- M38c ---------- http://httpd.chello.nl/k.vangelder ---+

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#include <ruby.h>

VALUE rb_cBla;

typedef struct Bla {
  char str[123456];
} Bla;

void bla_free(Bla *bla) {
  free(bla);
  // fprintf(stderr, "#");
}

VALUE bla_new() {
  VALUE info;
  Bla *one = ALLOC(Bla);
  info = Data_Wrap_Struct(rb_cBla, 0, bla_free, one);
  // rb_obj_call_init(info, 0, 0);
  return info;
}

void Init_native(void) {
  rb_cBla = rb_define_class("Bla", rb_cObject);
  rb_define_module_function(rb_cBla, "new", bla_new, 0);
}

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require 'test/native'

12345.times {
  Bla.new()
}

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require 'mkmf'
create_makefile("native")

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