[perl #75742] hints/openbsd.sh - usemymalloc slows down newer openbsd

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# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=75742 >



This is a bug report for perl from [email protected],
generated with the help of perlbug 1.39 running under perl 5.10.1.


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[Please describe your issue here]

Hi,

the hints file for openbsd contains the idea, that openbsd has a better
malloc than perl. This is far from true for openbsd > 3.7 where it 
replaced the malloc with a mmap based which can reclaim memory. 
While this malloc might perform good for other applications it is a
nightmare for perl, slowing it down by a factor of up to 2.5 !

To get this number the following simple Benchmark was used:

    1  for( my $i=0;$i<100000;$i++ ) {
    2      my @x = map { $i } (1..100);
    3      my $x = join('',@x);
    4      @x = split('',$x);
    5  }

While this benchmark is artificial we noticed the heavy slowdown also
with real world application which prompted us to compile our own perl
with usemymalloc=y.
Another slowdown is useshrplib (25%).

Slowdowns with these options are also on Linux (Ubuntu 10.04: 
usemymalloc=n: 15%, useshrplib=y: 20%).

If you want more of these unscientific results see my talk (in german) 
at the german perl: workshop http://maulwuff.de/pws/2010/ccopt.html.

Regards,
Steffen





[Please do not change anything below this line]
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---
Flags:
    category=install
    severity=medium
---
Site configuration information for perl 5.10.1:

Configured by Debian Project at Fri Apr 23 07:59:14 UTC 2010.

Summary of my perl5 (revision 5 version 10 subversion 1) configuration:
   
  Platform:
    osname=linux, osvers=2.6.24-27-server, archname=i486-linux-gnu-thread-multi
    uname='linux vernadsky 2.6.24-27-server #1 smp fri mar 12 01:45:06 utc 2010 i686 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.10 -Darchlib=/usr/lib/perl/5.10 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.10.1 -Dsitearch=/usr/local/lib/perl/5.10.1 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.10.1 -Dd_dosuid -des'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=undef, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -g',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.4.3', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /usr/lib64
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=/lib/libc-2.11.1.so, so=so, useshrplib=true, libperl=libperl.so.5.10.1
    gnulibc_version='2.11.1'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -g -L/usr/local/lib -fstack-protector'

Locally applied patches:
    

---
@INC for perl 5.10.1:
    /etc/perl
    /usr/local/lib/perl/5.10.1
    /usr/local/share/perl/5.10.1
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.10
    /usr/share/perl/5.10
    /usr/local/lib/site_perl
    .

---
Environment for perl 5.10.1:
    HOME=/home/steffen
    LANG=en_US.UTF-8
    LANGUAGE=
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/steffen/genua/bin:/home/steffen/bin:/Users/Shared/Software/perl-5.8.7/bin:/Users/Shared/Software/sqlite3/bin:/usr/lib/postgresql/8.3/bin/:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
    PERL_BADLANG (unset)
    SHELL=/bin/bash