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[perl #96802] Simple regex chews CPU/time

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From:
Tuc
Date:
August 11, 2011 15:13
Subject:
[perl #96802] Simple regex chews CPU/time
Message ID:
rt-3.6.HEAD-31297-1313078719-1295.96802-75-0@perl.org
# New Ticket Created by  Tuc 
# Please include the string:  [perl #96802]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org:443/rt3/Ticket/Display.html?id=96802 >


This is a bug report for perl from perl@t-b-o-h.net,
generated with the help of perlbug 1.26 running under perl 5.008005.


-----------------------------------------------------------------
[Please enter your report here]

Attached is a tar/gz with a perl program and a file. During running on
my system detailed below it takes:

vjofn# time perl whatthe.pl
1062.651u 0.523s 18:51.18 93.9% 10+845k 0+0io 0pf+0w

On a friends 5.12.4 it took 2m28.657s 

On a 5.8.8 , oddly:
[tuc@valhalla DG]$ time perl whatthe.pl

real    0m0.009s
user    0m0.005s
sys     0m0.004s

I don't think its such a hefty regex that it should kill the CPU and take
so long.

Thanks


[Please do not change anything below this line]
-----------------------------------------------------------------

---
This perlbug was built using Perl 5.00503 - Sun Mar  5 13:39:27 SAST 2000
It is being executed now by  Perl 5.008005 - Mon Oct 25 17:02:43 EDT 2004.

Site configuration information for perl 5.008005:

Configured by root at Mon Oct 25 17:02:43 EDT 2004.

Summary of my perl5 (revision 5 version 8 subversion 5) configuration:
  Platform:
    osname=freebsd, osvers=4.10-stable, archname=i386-freebsd-64int
    uname='freebsd vjofn.tucs-beachin-obx-house.com 4.10-stable freebsd 4.10-stable #11: tue oct 19 11:38:04 edt 2004 root@vjofn.tucs-beachin-obx-house.com:usrobjusrsrcsysvjofn i386 '
    config_args='-sde -Dprefix=/usr/local -Darchlib=/usr/local/lib/perl5/5.8.5/mach -Dprivlib=/usr/local/lib/perl5/5.8.5 -Dman3dir=/usr/local/lib/perl5/5.8.5/perl/man/man3 -Dman1dir=/usr/local/man/man1 -Dsitearch=/usr/local/lib/perl5/site_perl/5.8.5/mach -Dsitelib=/usr/local/lib/perl5/site_perl/5.8.5 -Dscriptdir=/usr/local/bin -Dsiteman3dir=/usr/local/lib/perl5/5.8.5/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Ui_malloc -Ui_iconv -Uinstallusrbinperl -Dcc=cc -Doptimize=-O -pipe -march=pentiumpro -Duseshrplib -Dccflags=-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.5/BSDPAN" -Dd_dosuid=define -Ui_gdbm -Dusethreads=n -Dusemymalloc=y -Duse64bitint'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=define use64bitall=undef uselongdouble=undef
    usemymalloc=y, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.5/BSDPAN" -DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -fno-strict-aliasing -pipe -I/usr/local/include',
    optimize='-O -pipe -march=pentiumpro',
    cppflags='-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.5/BSDPAN" -DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='2.95.4 20020320 [FreeBSD]', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags ='-Wl,-E  -L/usr/local/lib'
    libpth=/usr/lib /usr/local/lib
    libs=-lgdbm -lm -lcrypt -lutil -lc
    perllibs=-lm -lcrypt -lutil -lc
    libc=, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='  -Wl,-R/usr/local/lib/perl5/5.8.5/mach/CORE'
    cccdlflags='-DPIC -fPIC', lddlflags='-shared  -L/usr/local/lib'

Locally applied patches:
    

---
@INC for perl 5.008005:
    /usr/local/lib/perl5/site_perl/5.8.5/mach
    /usr/local/lib/perl5/site_perl/5.8.5
    /usr/local/lib/perl5/site_perl
    /usr/local/lib/perl5/5.8.5/BSDPAN
    /usr/local/lib/perl5/5.8.5/mach
    /usr/local/lib/perl5/5.8.5
    .

---
Environment for perl 5.008005:
    HOME=/root
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/games:/usr/local/sbin:/usr/local/bin:/usr/X11R6/bin:/root/bin
    PERL_BADLANG (unset)
    SHELL=/bin/csh

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