in reply to Re^3: sorting two arrays together
in thread sorting two arrays together

I don't trust Devel::Size, I prefer measuring externally: 
my @a;
my @b;

for (0 .. 2 ** 16 - 1) {
    if ($ARGV[0]) { 
        $a[$_][0] = $_;
        $a[$_][1] = $_;
    }
    else {
        @a[$_] = $_;
        @b[$_] = $_;
    }
}

system "grep ^VmSize /proc/$$/status";

__END__

[download]
Without an argument, I get VmSize: 11460 kB, with an argument I get VmSize: 16636 kB. Repeated runs vary by less than 10 kB. That's a difference of 45%.

However, I do notice a difference using total_size as well. Adding a say total_size(\@a) + total_size(\@b); at the end, I get: 

VmSize:       11844 kB
3670208

[download]
and 
VmSize:       16996 kB
10748112

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Almost 3 times the amount of memory with array pairs than without, according to Devel::Size;

Replies are listed 'Best First'.
Re^5: sorting two arrays together
by Anonyrnous Monk (Hermit) on Dec 23, 2010 at 00:11 UTC

    Just tried again with the Devel::Size version 0.71. With this I get (which makes more sense): 

    15204688   # pairs
7340704    # 2 arrays

    [download]

    The randomness in the results is also gone.

    I was using BrowserUk's patched version 0.72, which I thought fixed some issues he had discovered with the 'official' version — apparently there are other issues...

[reply]
[d/l]
      I was using BrowserUk's patched version 0.72,

      Could you post your platform/version details please.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]

        Sure: 

        $ perl -V
Summary of my perl5 (revision 5 version 10 subversion 1) configuration
+:
   
  Platform:
    osname=linux, osvers=2.6.24-24-generic, archname=x86_64-linux-thre
+ad-multi
    uname='linux tofana 2.6.24-24-generic #1 smp fri jul 24 22:15:50 u
+tc 2009 x86_64 gnulinux '
    config_args='-Dusethreads'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=und
+ef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing
+ -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_
+FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -f
+stack-protector -I/usr/local/include'
    ccversion='', gccversion='4.2.4 (Ubuntu 4.2.4-1ubuntu3)', gccosand
+vers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=1
+6
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t',
+ lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64
    libs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    libc=/lib/libc-2.7.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.7'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstac
+k-protector'


Characteristics of this binary (from libperl): 
  Compile-time options: MULTIPLICITY PERL_DONT_CREATE_GVSV
                        PERL_IMPLICIT_CONTEXT PERL_MALLOC_WRAP USE_64_
+BIT_ALL
                        USE_64_BIT_INT USE_ITHREADS USE_LARGE_FILES
                        USE_PERLIO USE_REENTRANT_API
  Built under linux
  Compiled at Mar 26 2010 08:03:08
  @INC:
    /usr/local/lib/perl5/5.10.1/x86_64-linux-thread-multi
    /usr/local/lib/perl5/5.10.1
    /usr/local/lib/perl5/site_perl/5.10.1/x86_64-linux-thread-multi
    /usr/local/lib/perl5/site_perl/5.10.1
    .

        [download]

        (If you need more info, or want me to try out some modification or something, just ask...)

[reply]
[d/l]

In Section Seekers of Perl Wisdom