possible memory leak in Socket or gethostbyaddr()?

[p5pRT]

Migrated from rt.perl.org#1042 (status was 'resolved')

Searchable as RT1042$

[p5pRT]

From [email protected]

(Redhat appears to have not included perlbug in their 6.0 distribution,
so I am using an older perlbug from a distribution I built myself.
This is, however, running via the perl(1) included with redhat 6.0,
which is the one I am noticing the problem with.)

I had been running a script I wrote to resolve the PTRs of several
/16 networks, when I heard significant swapping about halfway through
the list.

I checked vmstat​:

# vmstat 5 3
  procs memory swap io system cpu
r b w swpd free buff cache si so bi bo in cs us sy id
0 0 0 27592 17912 10204 18560 0 0 3 3 72 53 2 0 98
0 0 0 27592 17876 10204 18572 0 0 2 1 123 59 0 0 100
1 0 0 27592 17872 10204 18572 0 0 0 4 124 55 0 0 99

Then top​:

  PID USER PRI NI SIZE RSS SHARE STAT LIB %CPU %MEM TIME COMMAND
  850 root 6 0 82204 59M 404 S 0 0.2 47.2 3​:49 ns.pl

Here is the script​:

***

#!/usr/bin/perl -w

use Socket;

while (<>) {

  my ($iaddr, $hname);
  $| = 3.14;

  chomp;
  unless ($iaddr = inet_aton("$_")) {
  print STDERR "Bad input​: $_\n";
  next;
  }
  unless ($hname = gethostbyaddr($iaddr, AF_INET)) {
  print STDERR "No ptr for $_\n";
  next;
  }

  print $hname, "\n";

}
***

The ouput was then redirected to a file. The file of IPs being read is
only 17M , and a running perl is usually less than 3M on this box.

This is pretty extreme use of perl, so I don't expect a high priority
to be placed on this report; however, the script will most likely be
running for another day or so, so if you would like any more info about
the running perl, please let me know.

Thanks,

--
Au

PS​: named crashed after expiring ~22000 rr from it's cache while I was
writing this report, so perl isnt the only thing unprepared for this
weird situation...

Perl Info

This perlbug was built using Perl 5.00502 - Mon Nov 30 03:25:42 PST 1998
It is being executed now by  Perl 5.00503 - Tue Apr  6 23:33:05 EDT 1999.

Site configuration information for perl 5.00503:

Configured by root at Tue Apr  6 23:33:05 EDT 1999.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=linux, osvers=2.2.1-ac1, archname=i386-linux
    uname='linux porky.devel.redhat.com 2.2.1-ac1 #1 smp mon feb 1 17:44:44 est 1999 i686 unknown '
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='cc', optimize='-O2', gccversion=egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)
    cppflags='-Dbool=char -DHAS_BOOL -I/usr/local/include'
    ccflags ='-Dbool=char -DHAS_BOOL -I/usr/local/include'
    stdchar='char', d_stdstdio=undef, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lndbm -lgdbm -ldb -ldl -lm -lc -lposix -lcrypt
    libc=, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    


@INC for perl 5.00503:
    /usr/lib/perl5/5.00503/i386-linux
    /usr/lib/perl5/5.00503
    /usr/lib/perl5/site_perl/5.005/i386-linux
    /usr/lib/perl5/site_perl/5.005
    .


Environment for perl 5.00503:
    HOME=/home/anthonyu
    LANG (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/bin:/usr/bin:/usr/local/bin:/usr/bin/X11:/usr/X11R6/bin
    PERL_BADLANG (unset)
    SHELL=/bin/bash

[p5pRT]

@gbarr - Status changed from 'open' to 'resolved'

[p5pRT]

From @gbarr

This seems to be fixed in perl 5.6.0