Interpreting the Meaning of Time Method in Proc::ProcessTable

[monkfan]

I have a following snippet:

use Proc::ProcessTable;  
my $now = time;
print "NOW:", scalar(localtime $now),"\n";

$t      = new Proc::ProcessTable;
printf( $FORMAT,  "START", "HOWLONG", "CMD"  );
foreach $p ( @{ $t->table } ) {
 
    printf( $FORMAT,
        scalar( localtime( $p->start ) ), $p->time, 
        );

    }

}

And it prints:

NOW  :Fri Oct 26 17:37:58 2007

and in one of the entry it prints: prints:

START                    HOWLONG
Fri Oct 26 03:23:00 2007 120000

I was wondering what does the figure 12000 mean? The doc doesn't seem to describe it tangibly:

time        user + system time

Does that figure describe howlong a particular program is running? Is that in seconds?

[kyle]

It's how much CPU time the process has used (in seconds, I assume). 'User' time is how much time was spent in the program itself and 'system' time is how much time was spent in the operating system servicing the program's requests.

Update: Upon further reflection, I don't think that time is in seconds. Proc::ProcessTable::Process says that utime is in 1/100s of seconds, so that's probably what time is in too. Your 120000 figure is 33 hours as seconds and 20 minutes as 1/100s of seconds. If you're still in doubt, you could see what it says about "perl -e '$i++ while 1'" after ten seconds. My guess is it will be about 1000.

[jimsearle]

Sorry, but I still don't get it... ProcessTable says this:

PID    PPID   SIZE         RSS          TIME         COMMAND
19524  14920  936000       762796       55550000     /tools/atoptech/AP_07.06-06.27/Linux/bin/rhel3-64/AP 

and ps says this about the same process:

% ps -o 'ppid pid vsz rss time command'
 PPID   PID   VSZ  RSS     TIME COMMAND
14920 19524 936000 762796 00:00:55 /tools/atoptech/AP_07.06-06.27/Linux/bin/rhel3-64/AP

Thanks, Jim

[kyle]

It looks as if ps is reporting time in seconds (hours, minutes, seconds, separated by colons) and Proc::ProcessTable is reporting it in microseconds. If what you have is microseconds, you can convert that to seconds by dividing by one million.

my $microseconds = 55550000;
my $seconds = $microseconds / 1_000_000;

[karlgoethebier]

kyle is right. From README.linux:

SUPPORTED ATTRIBUTES
====================
  uid         UID of process
  euid          Effective UID of process
  suid          Saved UID of process
  fuid           File UID of process
  gid         GID of process
  egid          Effective GID of process
  sgid          Saved GID of process
  fgid           File GID of process
  pid         process ID
  ppid        parent process ID
  pgrp        process group
  sess        session ID
  priority    priority of process
  ttynum      tty number of process
  flags       flags of process
  minflt      minor page faults              
  cminflt     child minor page faults        
  majflt      major page faults              
  cmajflt     child major page faults        
  utime       user mode time (microseconds)
  stime       kernel mode time (microseconds)      
  cutime      child utime (microseconds)
  cstime      child stime (microseconds)
  time        user + system time (microseconds)
  ctime       child user + system time (microseconds)
  size        virtual memory size (bytes)
  rss         resident set size (bytes)
  wchan       address of current system call 
  fname       file name
  start       start time (seconds since the epoch)
  pctcpu      percent cpu used since process started
  state       state of process
  pctmem      percent memory
  cmndline    full command line of process
  exec        absolute filename (including path) of executed command
  ttydev      path of process's tty
  cwd         current directory of process

NOTE
====
This now correctly gives you microseconds.  Previously all times were 
+actually
in milliseconds even though this file said microseconds.
    -Jason Smith

BUGS
====
Though times are now converted to microseconds, they are limited to ji
+ffie
resolution.  A jiffie is 100 Hertz on most platforms, 1024 Hertz on Al
+pha. 
    -Philip Gwyn

Regards, Karl