Finding bottlenecks in your PHP code (From : http://www.codediesel.com/testing/finding-bottlenecks-in-your-php-code)

log-bottlenecks-php

$fplog = fopen("logb.txt", "a+");
$lastlogtime = time();
 
function log_time($logtext)
{
    global $fplog, $lastlogtime;
    $nowtime = time();
    $diff = $nowtime - $lastlogtime;
 
    fwrite($fplog, sprintf("%-30s | %-30s | %-3d", $logtext,  date('F Y h:i:s A', $nowtime), $diff) . PHP_EOL);
    $lastlogtime = $nowtime;
}

log_time("Start");
.
.// code
.
log_time("CertainActionController");
.
..// code
.
log_time("AfterActionController");
.
..// code
.
log_time("AfterLastCodeBlock");
fwrite($fplog, PHP_EOL . "----------------------" . PHP_EOL); 
fclose($fplog);