Check distribution of fastcgi processes over the hyperthreads and cores of your server

checkhyperthreads.php

<?php

// Are your fastcgi processes spread out evenly over the available hyperthreads on your server? 
// This script will tell you. 
//
// If your php-cgi process is not /usr/local/bin/php-cgi, tweak accordingly.
//
// In my experience they do tend to distribute pretty well over time, but see also
// assignhyperthreads.php.
//
// [email protected], @boutell, punkave.com

$pids = glob("/proc/*");

$hyperthreadsTotal = count(preg_grep('/^processor/', file('/proc/cpuinfo')));

echo("Total hyperthreads: $hyperthreadsTotal\n");

for ($i = 0; ($i < $hyperthreadsTotal); $i++)
{
  $cpus[$i] = 0;
}

foreach ($pids as $pid)
{
  $pid = basename($pid);
  if (preg_match('/^\d+$/', $pid))
  {
    $cmd = file_get_contents("/proc/$pid/cmdline");
    $elements = explode("\x00", $cmd);
    if (count($elements))
    {
      if ($elements[0] === '/usr/local/bin/php-cgi')
      {
        $stat = file_get_contents("/proc/$pid/stat");
        $columns = explode(' ', $stat);
        $cpu = $columns[38];
        $cpus[$cpu]++;
        $total++;
      }
    }
  }
}

echo("Total fastcgi processes: $total\n");
for ($i = 0; ($i < $hyperthreadsTotal); $i++)
{
  echo($cpus[$i] . "\n");
}